diff --git a/core/modules/layout_builder/src/Controller/MoveBlockController.php b/core/modules/layout_builder/src/Controller/MoveBlockController.php
index d1b26a2534..e014fc5ab9 100644
--- a/core/modules/layout_builder/src/Controller/MoveBlockController.php
+++ b/core/modules/layout_builder/src/Controller/MoveBlockController.php
@@ -93,10 +93,10 @@ public function build(EntityInterface $entity, $delta_from, $delta_to, $region_f
     // If a preceding block was specified, insert after that. Otherwise add the
     // block to the front.
     if (isset($preceding_block_uuid)) {
-      $section->insertBlock($region_to, [$block_uuid => $block], $preceding_block_uuid);
+      $section->insertBlock($region_to, $block_uuid, $block, $preceding_block_uuid);
     }
     else {
-      $section->addBlock($region_to, [$block_uuid => $block]);
+      $section->addBlock($region_to, $block_uuid, $block);
     }
 
     $field->updateFromSection($section);
diff --git a/core/modules/layout_builder/src/Form/AddBlockForm.php b/core/modules/layout_builder/src/Form/AddBlockForm.php
index e55106cd57..1757606002 100644
--- a/core/modules/layout_builder/src/Form/AddBlockForm.php
+++ b/core/modules/layout_builder/src/Form/AddBlockForm.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\layout_builder\Form;
 
+use Drupal\layout_builder\Section;
+
 /**
  * Provides a form to add a block.
  *
@@ -23,4 +25,11 @@ protected function submitLabel() {
     return $this->t('Add Block');
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  protected function submitBlock(Section $section, $region, $uuid, array $configuration) {
+    $section->addBlock($region, $uuid, $configuration);
+  }
+
 }
diff --git a/core/modules/layout_builder/src/Form/ConfigureBlockFormBase.php b/core/modules/layout_builder/src/Form/ConfigureBlockFormBase.php
index a7539611cc..de6b878328 100644
--- a/core/modules/layout_builder/src/Form/ConfigureBlockFormBase.php
+++ b/core/modules/layout_builder/src/Form/ConfigureBlockFormBase.php
@@ -17,6 +17,7 @@
 use Drupal\Core\Plugin\PluginWithFormsInterface;
 use Drupal\layout_builder\Controller\LayoutRebuildFormTrait;
 use Drupal\layout_builder\LayoutTempstoreRepositoryInterface;
+use Drupal\layout_builder\Section;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\RequestStack;
 
@@ -212,6 +213,20 @@ public function buildForm(array $form, FormStateInterface $form_state, EntityInt
    */
   abstract protected function submitLabel();
 
+  /**
+   * Handles the submission of a block.
+   *
+   * @param \Drupal\layout_builder\Section $section
+   *   The layout section.
+   * @param string $region
+   *   The region name.
+   * @param string $uuid
+   *   The UUID of the block.
+   * @param array $configuration
+   *   The block configuration.
+   */
+  abstract protected function submitBlock(Section $section, $region, $uuid, array $configuration);
+
   /**
    * {@inheritdoc}
    */
@@ -238,8 +253,7 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
     /** @var \Drupal\layout_builder\Field\LayoutSectionItemInterface $field */
     $field = $this->entity->layout_builder__layout->get($this->delta);
     $section = $field->getSection();
-    $block = &$section->getBlock($this->region, $configuration['uuid']);
-    $block['block'] = $configuration;
+    $this->submitBlock($section, $this->region, $configuration['uuid'], ['block' => $configuration]);
     $field->updateFromSection($section);
 
     $this->layoutTempstoreRepository->set($this->entity);
diff --git a/core/modules/layout_builder/src/Form/UpdateBlockForm.php b/core/modules/layout_builder/src/Form/UpdateBlockForm.php
index bfef3dc020..2f2aa600e4 100644
--- a/core/modules/layout_builder/src/Form/UpdateBlockForm.php
+++ b/core/modules/layout_builder/src/Form/UpdateBlockForm.php
@@ -4,6 +4,7 @@
 
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\layout_builder\Section;
 
 /**
  * Provides a form to update a block.
@@ -56,4 +57,11 @@ protected function submitLabel() {
     return $this->t('Update');
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  protected function submitBlock(Section $section, $region, $uuid, array $configuration) {
+    $section->updateBlock($region, $uuid, $configuration);
+  }
+
 }
diff --git a/core/modules/layout_builder/src/Section.php b/core/modules/layout_builder/src/Section.php
index ba4307e1f9..f5e19003b5 100644
--- a/core/modules/layout_builder/src/Section.php
+++ b/core/modules/layout_builder/src/Section.php
@@ -51,7 +51,7 @@ public function getValue() {
    * @throws \InvalidArgumentException
    *   Thrown when the expected region or UUID do not exist.
    */
-  public function &getBlock($region, $uuid) {
+  public function getBlock($region, $uuid) {
     if (!isset($this->section[$region])) {
       throw new \InvalidArgumentException('Invalid region');
     }
@@ -70,7 +70,7 @@ public function &getBlock($region, $uuid) {
    *   The region name.
    * @param string $uuid
    *   The UUID of the block to retrieve.
-   * @param array $block
+   * @param array $configuration
    *   The block configuration.
    *
    * @return $this
@@ -78,7 +78,7 @@ public function &getBlock($region, $uuid) {
    * @throws \InvalidArgumentException
    *   Thrown when the expected region or UUID do not exist.
    */
-  public function updateBlock($region, $uuid, array $block) {
+  public function updateBlock($region, $uuid, array $configuration) {
     if (!isset($this->section[$region])) {
       throw new \InvalidArgumentException('Invalid region');
     }
@@ -87,7 +87,7 @@ public function updateBlock($region, $uuid, array $block) {
       throw new \InvalidArgumentException('Invalid UUID');
     }
 
-    $this->section[$region][$uuid] = $block;
+    $this->section[$region][$uuid] = $configuration;
 
     return $this;
   }
@@ -113,14 +113,16 @@ public function removeBlock($region, $uuid) {
    *
    * @param string $region
    *   The region name.
-   * @param array $block
-   *   The block.
+   * @param string $uuid
+   *   The UUID of the block to add.
+   * @param array $configuration
+   *   The block configuration.
    *
    * @return $this
    */
-  public function addBlock($region, array $block) {
+  public function addBlock($region, $uuid, array $configuration) {
     $this->section += [$region => []];
-    $this->section[$region] = array_merge($block, $this->section[$region]);
+    $this->section[$region] = array_merge([$uuid => $configuration], $this->section[$region]);
     return $this;
   }
 
@@ -129,8 +131,10 @@ public function addBlock($region, array $block) {
    *
    * @param string $region
    *   The region name.
-   * @param array $block
-   *   The block to insert.
+   * @param string $uuid
+   *   The UUID of the block to insert.
+   * @param array $configuration
+   *   The block configuration.
    * @param string $preceding_uuid
    *   The UUID of the existing block to insert after.
    *
@@ -139,7 +143,7 @@ public function addBlock($region, array $block) {
    * @throws \InvalidArgumentException
    *   Thrown when the expected region does not exist.
    */
-  public function insertBlock($region, array $block, $preceding_uuid) {
+  public function insertBlock($region, $uuid, array $configuration, $preceding_uuid) {
     if (!isset($this->section[$region])) {
       throw new \InvalidArgumentException('Invalid region');
     }
@@ -151,7 +155,7 @@ public function insertBlock($region, array $block, $preceding_uuid) {
 
     $before = array_slice($this->section[$region], 0, $slice_id + 1);
     $after = array_slice($this->section[$region], $slice_id + 1);
-    $this->section[$region] = array_merge($before, $block, $after);
+    $this->section[$region] = array_merge($before, [$uuid => $configuration], $after);
     return $this;
   }
 
diff --git a/core/modules/layout_builder/tests/src/Unit/LayoutSectionTest.php b/core/modules/layout_builder/tests/src/Unit/LayoutSectionTest.php
deleted file mode 100644
index 711f38dfd5..0000000000
--- a/core/modules/layout_builder/tests/src/Unit/LayoutSectionTest.php
+++ /dev/null
@@ -1,130 +0,0 @@
-<?php
-
-namespace Drupal\Tests\layout_builder\Unit;
-
-use Drupal\layout_builder\Section;
-use Drupal\Tests\UnitTestCase;
-
-/**
- * @coversDefaultClass \Drupal\layout_builder\LayoutSection
- * @group layout_builder
- */
-class LayoutSectionTest extends UnitTestCase {
-
-  /**
-   * @covers ::__construct
-   * @covers ::getValue
-   */
-  public function testGetValue() {
-    $expected = [
-      'empty-region' => [],
-      'some-region' => [
-        'some-uuid' => [
-          'block' => [
-            'id' => 'some-block-id',
-          ],
-        ],
-      ],
-    ];
-    $section = new Section($expected);
-    $this->assertSame($expected, $section->getValue());
-  }
-
-  /**
-   * @covers ::getBlock
-   */
-  public function testGetBlockInvalidRegion() {
-    $section = new Section([]);
-    $this->setExpectedException(\InvalidArgumentException::class, 'Invalid region');
-    $section->getBlock('invalid', 'valid-uuid');
-  }
-
-  /**
-   * @covers ::getBlock
-   */
-  public function testGetBlockInvalidUuid() {
-    $section = new Section(['top' => []]);
-    $this->setExpectedException(\InvalidArgumentException::class, 'Invalid UUID');
-    $section->getBlock('top', 'invalid-uuid');
-  }
-
-  /**
-   * @covers ::getBlock
-   */
-  public function testGetBlock() {
-    $section = new Section(['top' => ['valid-uuid' => ['block' => ['id' => 'some_block_id']]]]);
-    $expected = ['block' => ['id' => 'some_block_id']];
-
-    $block = $section->getBlock('top', 'valid-uuid');
-    $this->assertSame($expected, $block);
-  }
-
-  /**
-   * @covers ::removeBlock
-   */
-  public function testRemoveBlock() {
-    $section = new Section(['top' => ['existing-uuid' => []]]);
-    $section->removeBlock('top', 'existing-uuid');
-    $expected = [];
-    $this->assertSame($expected, $section->getValue());
-  }
-
-  /**
-   * @covers ::addBlock
-   */
-  public function testAddBlock() {
-    $section = new Section(['top' => ['existing-uuid' => []]]);
-    $section->addBlock('top', ['new-uuid' => []]);
-    $expected = [
-      'top' => [
-        'new-uuid' => [],
-        'existing-uuid' => [],
-      ],
-    ];
-    $this->assertSame($expected, $section->getValue());
-  }
-
-  /**
-   * @covers ::insertBlock
-   */
-  public function testInsertBlock() {
-    $section = new Section([
-      'top' => [
-        'first-uuid' => [],
-        'second-uuid' => [],
-      ],
-    ]);
-    $section->insertBlock('top', ['new-uuid' => []], 'first-uuid');
-    $expected = [
-      'top' => [
-        'first-uuid' => [],
-        'new-uuid' => [],
-        'second-uuid' => [],
-      ],
-    ];
-    $this->assertSame($expected, $section->getValue());
-  }
-
-  /**
-   * @covers ::insertBlock
-   */
-  public function testInsertBlockInvalidRegion() {
-    $section = new Section([]);
-    $this->setExpectedException(\InvalidArgumentException::class, 'Invalid region');
-    $section->insertBlock('top', [], 'first-uuid');
-  }
-
-  /**
-   * @covers ::insertBlock
-   */
-  public function testInsertBlockInvalidUuid() {
-    $section = new Section([
-      'top' => [
-        'second-uuid' => [],
-      ],
-    ]);
-    $this->setExpectedException(\InvalidArgumentException::class, 'Invalid preceding UUID');
-    $section->insertBlock('top', [], 'first-uuid');
-  }
-
-}
diff --git a/core/modules/layout_builder/tests/src/Unit/SectionTest.php b/core/modules/layout_builder/tests/src/Unit/SectionTest.php
new file mode 100644
index 0000000000..33a338706e
--- /dev/null
+++ b/core/modules/layout_builder/tests/src/Unit/SectionTest.php
@@ -0,0 +1,265 @@
+<?php
+
+namespace Drupal\Tests\layout_builder\Unit;
+
+use Drupal\layout_builder\Section;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\layout_builder\Section
+ * @group layout_builder
+ */
+class SectionTest extends UnitTestCase {
+
+  /**
+   * The section object to test.
+   *
+   * @var \Drupal\layout_builder\Section
+   */
+  protected $section;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->section = new Section([
+      'empty-region' => [],
+      'some-region' => [
+        'existing-uuid' => [
+          'block' => [
+            'id' => 'existing-block-id',
+          ],
+        ],
+      ],
+      'ordered-region' => [
+        'first-uuid' => [
+          'block' => [
+            'id' => 'first-block-id',
+          ],
+        ],
+        'second-uuid' => [
+          'block' => [
+            'id' => 'second-block-id',
+          ],
+        ],
+      ],
+    ]);
+  }
+
+  /**
+   * @covers ::__construct
+   * @covers ::getValue
+   */
+  public function testGetValue() {
+    $expected = [
+      'empty-region' => [],
+      'some-region' => [
+        'existing-uuid' => [
+          'block' => [
+            'id' => 'existing-block-id',
+          ],
+        ],
+      ],
+      'ordered-region' => [
+        'first-uuid' => [
+          'block' => [
+            'id' => 'first-block-id',
+          ],
+        ],
+        'second-uuid' => [
+          'block' => [
+            'id' => 'second-block-id',
+          ],
+        ],
+      ],
+    ];
+    $result = $this->section->getValue();
+    $this->assertSame($expected, $result);
+  }
+
+  /**
+   * @covers ::getBlock
+   */
+  public function testGetBlockInvalidRegion() {
+    $this->setExpectedException(\InvalidArgumentException::class, 'Invalid region');
+    $this->section->getBlock('invalid-region', 'existing-uuid');
+  }
+
+  /**
+   * @covers ::getBlock
+   */
+  public function testGetBlockInvalidUuid() {
+    $this->setExpectedException(\InvalidArgumentException::class, 'Invalid UUID');
+    $this->section->getBlock('some-region', 'invalid-uuid');
+  }
+
+  /**
+   * @covers ::getBlock
+   */
+  public function testGetBlock() {
+    $expected = ['block' => ['id' => 'existing-block-id']];
+
+    $block = $this->section->getBlock('some-region', 'existing-uuid');
+    $this->assertSame($expected, $block);
+  }
+
+  /**
+   * @covers ::removeBlock
+   */
+  public function testRemoveBlock() {
+    $this->section->removeBlock('some-region', 'existing-uuid');
+    $expected = [
+      'ordered-region' => [
+        'first-uuid' => [
+          'block' => [
+            'id' => 'first-block-id',
+          ],
+        ],
+        'second-uuid' => [
+          'block' => [
+            'id' => 'second-block-id',
+          ],
+        ],
+      ],
+    ];
+    $this->assertSame($expected, $this->section->getValue());
+  }
+
+  /**
+   * @covers ::addBlock
+   */
+  public function testAddBlock() {
+    $this->section->addBlock('some-region', 'new-uuid', []);
+    $expected = [
+      'empty-region' => [],
+      'some-region' => [
+        'new-uuid' => [],
+        'existing-uuid' => [
+          'block' => [
+            'id' => 'existing-block-id',
+          ],
+        ],
+      ],
+      'ordered-region' => [
+        'first-uuid' => [
+          'block' => [
+            'id' => 'first-block-id',
+          ],
+        ],
+        'second-uuid' => [
+          'block' => [
+            'id' => 'second-block-id',
+          ],
+        ],
+      ],
+    ];
+    $this->assertSame($expected, $this->section->getValue());
+  }
+
+  /**
+   * @covers ::insertBlock
+   */
+  public function testInsertBlock() {
+    $this->section->insertBlock('ordered-region', 'new-uuid', [], 'first-uuid');
+    $expected = [
+      'empty-region' => [],
+      'some-region' => [
+        'existing-uuid' => [
+          'block' => [
+            'id' => 'existing-block-id',
+          ],
+        ],
+      ],
+      'ordered-region' => [
+        'first-uuid' => [
+          'block' => [
+            'id' => 'first-block-id',
+          ],
+        ],
+        'new-uuid' => [],
+        'second-uuid' => [
+          'block' => [
+            'id' => 'second-block-id',
+          ],
+        ],
+      ],
+    ];
+    $this->assertSame($expected, $this->section->getValue());
+  }
+
+  /**
+   * @covers ::insertBlock
+   */
+  public function testInsertBlockInvalidRegion() {
+    $this->setExpectedException(\InvalidArgumentException::class, 'Invalid region');
+    $this->section->insertBlock('invalid-region', 'new-uuid', [], 'first-uuid');
+  }
+
+  /**
+   * @covers ::insertBlock
+   */
+  public function testInsertBlockInvalidUuid() {
+    $this->setExpectedException(\InvalidArgumentException::class, 'Invalid preceding UUID');
+    $this->section->insertBlock('ordered-region', 'new-uuid', [], 'invalid-uuid');
+  }
+
+  /**
+   * @covers ::updateBlock
+   */
+  public function testUpdateBlock() {
+    $this->section->updateBlock('some-region', 'existing-uuid', [
+      'block' => [
+        'id' => 'existing-block-id',
+        'settings' => [
+          'foo' => 'bar',
+        ],
+      ],
+    ]);
+
+    $expected = [
+      'empty-region' => [],
+      'some-region' => [
+        'existing-uuid' => [
+          'block' => [
+            'id' => 'existing-block-id',
+            'settings' => [
+              'foo' => 'bar',
+            ],
+          ],
+        ],
+      ],
+      'ordered-region' => [
+        'first-uuid' => [
+          'block' => [
+            'id' => 'first-block-id',
+          ],
+        ],
+        'second-uuid' => [
+          'block' => [
+            'id' => 'second-block-id',
+          ],
+        ],
+      ],
+    ];
+    $this->assertSame($expected, $this->section->getValue());
+  }
+
+  /**
+   * @covers ::updateBlock
+   */
+  public function testUpdateBlockInvalidRegion() {
+    $this->setExpectedException(\InvalidArgumentException::class, 'Invalid region');
+    $this->section->updateBlock('invalid-region', 'new-uuid', []);
+  }
+
+  /**
+   * @covers ::updateBlock
+   */
+  public function testUpdateBlockInvalidUuid() {
+    $this->setExpectedException(\InvalidArgumentException::class, 'Invalid UUID');
+    $this->section->updateBlock('ordered-region', 'new-uuid', []);
+  }
+
+}