diff --git a/src/Symfony/Component/VarExporter/Internal/LazyObjectState.php b/src/Symfony/Component/VarExporter/Internal/LazyObjectState.php
index 605f1fdd52831..99f721df2605c 100644
--- a/src/Symfony/Component/VarExporter/Internal/LazyObjectState.php
+++ b/src/Symfony/Component/VarExporter/Internal/LazyObjectState.php
@@ -55,16 +55,34 @@ public function initialize($instance, $propertyName, $propertyScope)
             $propertyScopes = Hydrator::$propertyScopes[$class];
             $propertyScopes[$k = "\0$propertyScope\0$propertyName"] ?? $propertyScopes[$k = "\0*\0$propertyName"] ?? $k = $propertyName;
 
-            if (!$initializer = $this->initializer[$k] ?? null) {
-                return self::STATUS_UNINITIALIZED_PARTIAL;
-            }
+            if ($initializer = $this->initializer[$k] ?? null) {
+                $value = $initializer(...[$instance, $propertyName, $propertyScope, LazyObjectRegistry::$defaultProperties[$class][$k] ?? null]);
+                $accessor = LazyObjectRegistry::$classAccessors[$propertyScope] ??= LazyObjectRegistry::getClassAccessors($propertyScope);
+                $accessor['set']($instance, $propertyName, $value);
 
-            $value = $initializer(...[$instance, $propertyName, $propertyScope, LazyObjectRegistry::$defaultProperties[$class][$k] ?? null]);
+                return $this->status = self::STATUS_INITIALIZED_PARTIAL;
+            }
 
-            $accessor = LazyObjectRegistry::$classAccessors[$propertyScope] ??= LazyObjectRegistry::getClassAccessors($propertyScope);
-            $accessor['set']($instance, $propertyName, $value);
+            $status = self::STATUS_UNINITIALIZED_PARTIAL;
+
+            if ($initializer = $this->initializer["\0"] ?? null) {
+                if (!\is_array($values = $initializer($instance, LazyObjectRegistry::$defaultProperties[$class]))) {
+                    throw new \TypeError(sprintf('The lazy-initializer defined for instance of "%s" must return an array, got "%s".', $class, get_debug_type($values)));
+                }
+                $properties = (array) $instance;
+                foreach ($values as $key => $value) {
+                    if ($k === $key) {
+                        $status = self::STATUS_INITIALIZED_PARTIAL;
+                    }
+                    if (!\array_key_exists($key, $properties) && [$scope, $name, $readonlyScope] = $propertyScopes[$key] ?? null) {
+                        $scope = $readonlyScope ?? ('*' !== $scope ? $scope : $class);
+                        $accessor = LazyObjectRegistry::$classAccessors[$scope] ??= LazyObjectRegistry::getClassAccessors($scope);
+                        $accessor['set']($instance, $name, $value);
+                    }
+                }
+            }
 
-            return $this->status = self::STATUS_INITIALIZED_PARTIAL;
+            return $status;
         }
 
         $this->status = self::STATUS_INITIALIZED_FULL;
diff --git a/src/Symfony/Component/VarExporter/LazyGhostTrait.php b/src/Symfony/Component/VarExporter/LazyGhostTrait.php
index 46346b6a7b0d7..df40c267fd027 100644
--- a/src/Symfony/Component/VarExporter/LazyGhostTrait.php
+++ b/src/Symfony/Component/VarExporter/LazyGhostTrait.php
@@ -29,16 +29,23 @@ trait LazyGhostTrait
      * properties and closures should accept 4 arguments: the instance to
      * initialize, the property to initialize, its write-scope, and its default
      * value. Each closure should return the value of the corresponding property.
+     * The special "\0" key can be used to define a closure that returns all
+     * properties at once when full-initialization is needed; it takes the
+     * instance and its default properties as arguments.
      *
      * Properties should be indexed by their array-cast name, see
      * https://php.net/manual/language.types.array#language.types.array.casting
      *
-     * @param \Closure(static):void|array<string, \Closure(static, string, ?string, mixed):mixed> $initializer
-     * @param array<string, true> $skippedProperties An array indexed by the properties to skip, aka the ones
-     *                                               that the initializer doesn't set when its a closure
+     * @param (\Closure(static):void
+     *        |array<string, \Closure(static, string, ?string, mixed):mixed>
+     *        |array{"\0": \Closure(static, array<string, mixed>):array<string, mixed>}) $initializer
+     * @param array<string, true>|null $skippedProperties An array indexed by the properties to skip, aka the ones
+     *                                                    that the initializer doesn't set when its a closure
      */
-    public static function createLazyGhost(\Closure|array $initializer, array $skippedProperties = [], self $instance = null): static
+    public static function createLazyGhost(\Closure|array $initializer, array $skippedProperties = null, self $instance = null): static
     {
+        $onlyProperties = null === $skippedProperties && \is_array($initializer) ? $initializer : null;
+
         if (self::class !== $class = $instance ? $instance::class : static::class) {
             $skippedProperties["\0".self::class."\0lazyObjectId"] = true;
         } elseif (\defined($class.'::LAZY_OBJECT_PROPERTY_SCOPES')) {
@@ -48,8 +55,7 @@ public static function createLazyGhost(\Closure|array $initializer, array $skipp
         $instance ??= (Registry::$classReflectors[$class] ??= new \ReflectionClass($class))->newInstanceWithoutConstructor();
         Registry::$defaultProperties[$class] ??= (array) $instance;
         $instance->lazyObjectId = $id = spl_object_id($instance);
-        Registry::$states[$id] = new LazyObjectState($initializer, $skippedProperties);
-        $onlyProperties = \is_array($initializer) ? $initializer : null;
+        Registry::$states[$id] = new LazyObjectState($initializer, $skippedProperties ??= []);
 
         foreach (Registry::$classResetters[$class] ??= Registry::getClassResetters($class) as $reset) {
             $reset($instance, $skippedProperties, $onlyProperties);
@@ -60,8 +66,10 @@ public static function createLazyGhost(\Closure|array $initializer, array $skipp
 
     /**
      * Returns whether the object is initialized.
+     *
+     * @param $partial Whether partially initialized objects should be considered as initialized
      */
-    public function isLazyObjectInitialized(): bool
+    public function isLazyObjectInitialized(bool $partial = false): bool
     {
         if (!$state = Registry::$states[$this->lazyObjectId ?? ''] ?? null) {
             return true;
@@ -73,6 +81,11 @@ public function isLazyObjectInitialized(): bool
 
         $class = $this::class;
         $properties = (array) $this;
+
+        if ($partial) {
+            return (bool) array_intersect_key($state->initializer, $properties);
+        }
+
         $propertyScopes = Hydrator::$propertyScopes[$class] ??= Hydrator::getPropertyScopes($class);
         foreach ($state->initializer as $key => $initializer) {
             if (!\array_key_exists($key, $properties) && isset($propertyScopes[$key])) {
@@ -100,6 +113,8 @@ public function initializeLazyObject(): static
             return $this;
         }
 
+        $values = isset($state->initializer["\0"]) ? null : [];
+
         $class = $this::class;
         $properties = (array) $this;
         $propertyScopes = Hydrator::$propertyScopes[$class] ??= Hydrator::getPropertyScopes($class);
@@ -107,9 +122,25 @@ public function initializeLazyObject(): static
             if (\array_key_exists($key, $properties) || ![$scope, $name, $readonlyScope] = $propertyScopes[$key] ?? null) {
                 continue;
             }
+            $scope = $readonlyScope ?? ('*' !== $scope ? $scope : $class);
 
-            $state->initialize($this, $name, $readonlyScope ?? ('*' !== $scope ? $scope : null));
-            $properties = (array) $this;
+            if (null === $values) {
+                if (!\is_array($values = ($state->initializer["\0"])($this, Registry::$defaultProperties[$class]))) {
+                    throw new \TypeError(sprintf('The lazy-initializer defined for instance of "%s" must return an array, got "%s".', $class, get_debug_type($values)));
+                }
+
+                if (\array_key_exists($key, $properties = (array) $this)) {
+                    continue;
+                }
+            }
+
+            if (\array_key_exists($key, $values)) {
+                $accessor = Registry::$classAccessors[$scope] ??= Registry::getClassAccessors($scope);
+                $accessor['set']($this, $name, $properties[$key] = $values[$key]);
+            } else {
+                $state->initialize($this, $name, $scope);
+                $properties = (array) $this;
+            }
         }
 
         return $this;
diff --git a/src/Symfony/Component/VarExporter/LazyObjectInterface.php b/src/Symfony/Component/VarExporter/LazyObjectInterface.php
index 314ba85e37039..36708845912ca 100644
--- a/src/Symfony/Component/VarExporter/LazyObjectInterface.php
+++ b/src/Symfony/Component/VarExporter/LazyObjectInterface.php
@@ -15,8 +15,10 @@ interface LazyObjectInterface
 {
     /**
      * Returns whether the object is initialized.
+     *
+     * @param $partial Whether partially initialized objects should be considered as initialized
      */
-    public function isLazyObjectInitialized(): bool;
+    public function isLazyObjectInitialized(bool $partial = false): bool;
 
     /**
      * Forces initialization of a lazy object and returns it.
diff --git a/src/Symfony/Component/VarExporter/LazyProxyTrait.php b/src/Symfony/Component/VarExporter/LazyProxyTrait.php
index d79806c086d5a..97509eb35321b 100644
--- a/src/Symfony/Component/VarExporter/LazyProxyTrait.php
+++ b/src/Symfony/Component/VarExporter/LazyProxyTrait.php
@@ -47,8 +47,10 @@ public static function createLazyProxy(\Closure $initializer, self $instance = n
 
     /**
      * Returns whether the object is initialized.
+     *
+     * @param $partial Whether partially initialized objects should be considered as initialized
      */
-    public function isLazyObjectInitialized(): bool
+    public function isLazyObjectInitialized(bool $partial = false): bool
     {
         if (0 >= ($this->lazyObjectId ?? 0)) {
             return true;
diff --git a/src/Symfony/Component/VarExporter/Tests/LazyGhostTraitTest.php b/src/Symfony/Component/VarExporter/Tests/LazyGhostTraitTest.php
index 44ef1f17eede9..3663217435268 100644
--- a/src/Symfony/Component/VarExporter/Tests/LazyGhostTraitTest.php
+++ b/src/Symfony/Component/VarExporter/Tests/LazyGhostTraitTest.php
@@ -248,6 +248,7 @@ public function testPartialInitialization()
         $this->assertFalse($instance->isLazyObjectInitialized());
         $this->assertSame(123, $instance->public);
         $this->assertFalse($instance->isLazyObjectInitialized());
+        $this->assertTrue($instance->isLazyObjectInitialized(true));
         $this->assertSame(['public', "\0".TestClass::class."\0lazyObjectId"], array_keys((array) $instance));
         $this->assertSame(1, $counter);
 
@@ -330,4 +331,89 @@ public function testReflectionPropertyGetValue()
 
         $this->assertSame(-3, $r->getValue($obj));
     }
+
+    public function testFullPartialInitialization()
+    {
+        $counter = 0;
+        $initializer = static function (ChildTestClass $instance, string $property, ?string $scope, mixed $default) use (&$counter) {
+            return 234;
+        };
+        $instance = ChildTestClass::createLazyGhost([
+            'public' => $initializer,
+            'publicReadonly' => $initializer,
+            "\0*\0protected" => $initializer,
+            "\0" => function ($obj, $defaults) use (&$instance, &$counter) {
+                $counter += 1000;
+                $this->assertSame($instance, $obj);
+
+                return [
+                    'public' => 345,
+                    'publicReadonly' => 456,
+                    "\0*\0protected" => 567,
+                ] + $defaults;
+            },
+        ]);
+
+        $this->assertSame($instance, $instance->initializeLazyObject());
+        $this->assertSame(345, $instance->public);
+        $this->assertSame(456, $instance->publicReadonly);
+        $this->assertSame(6, ((array) $instance)["\0".ChildTestClass::class."\0private"]);
+        $this->assertSame(3, ((array) $instance)["\0".TestClass::class."\0private"]);
+        $this->assertSame(1000, $counter);
+    }
+
+    public function testPartialInitializationFallback()
+    {
+        $counter = 0;
+        $instance = ChildTestClass::createLazyGhost([
+            "\0" => function ($obj) use (&$instance, &$counter) {
+                $counter += 1000;
+                $this->assertSame($instance, $obj);
+
+                return [
+                    'public' => 345,
+                    'publicReadonly' => 456,
+                    "\0*\0protected" => 567,
+                ];
+            },
+        ], []);
+
+        $this->assertSame(345, $instance->public);
+        $this->assertSame(456, $instance->publicReadonly);
+        $this->assertSame(567, ((array) $instance)["\0*\0protected"]);
+        $this->assertSame(1000, $counter);
+    }
+
+    public function testFullInitializationAfterPartialInitialization()
+    {
+        $counter = 0;
+        $initializer = static function (ChildTestClass $instance, string $property, ?string $scope, mixed $default) use (&$counter) {
+            ++$counter;
+
+            return 234;
+        };
+        $instance = ChildTestClass::createLazyGhost([
+            'public' => $initializer,
+            'publicReadonly' => $initializer,
+            "\0*\0protected" => $initializer,
+            "\0" => function ($obj, $defaults) use (&$instance, &$counter) {
+                $counter += 1000;
+                $this->assertSame($instance, $obj);
+
+                return [
+                    'public' => 345,
+                    'publicReadonly' => 456,
+                    "\0*\0protected" => 567,
+                ] + $defaults;
+            },
+        ]);
+
+        $this->assertSame(234, $instance->public);
+        $this->assertSame($instance, $instance->initializeLazyObject());
+        $this->assertSame(234, $instance->public);
+        $this->assertSame(456, $instance->publicReadonly);
+        $this->assertSame(6, ((array) $instance)["\0".ChildTestClass::class."\0private"]);
+        $this->assertSame(3, ((array) $instance)["\0".TestClass::class."\0private"]);
+        $this->assertSame(1001, $counter);
+    }
 }