Preheat the oven to 350°F (175°C) and grease a 9×13-inch (23×33 cm) baking dish.
Prepare the white cake mix according to the package instructions using the listed eggs, oil, and water. Pour the batter into the prepared baking dish and bake until a toothpick inserted in the center comes out clean, about 28 to 32 minutes.
1 box white cake mix, eggs, oil, and water as listed on the cake mix package.
Remove the cake from the oven and allow it to cool for 15 to 20 minutes. While the cake is still warm, use the handle of a wooden spoon or a thick skewer to poke holes evenly across the surface, spacing them about 1 inch (2.5 cm) apart and pressing down nearly to the bottom of the cake.
Pour the boiling water into a heat-safe measuring jug and stir in the strawberry gelatin until fully dissolved. Allow the mixture to cool for about 15 minutes before proceeding. Transfer the cooled gelatin mixture to a blender, add the fresh strawberries, and blend until completely smooth. Do not blend while the liquid is hot, as steam can cause pressure to build and force the blender lid off.
1 cup (240 ml) boiling water, 1 box (3 oz / 85 g) strawberry gelatin, 1 pint (~340 g) fresh strawberries
Slowly pour the strawberry mixture evenly over the cake, allowing it to seep into the holes and spread across the surface. Transfer the cake to the refrigerator and chill for at least 2 hours, or until the filling is fully set.
To make the frosting, add the softened cream cheese, confectioners’ sugar, vanilla, and cold heavy whipping cream to a large mixing bowl. Beat until smooth and creamy, stopping once soft peaks form. Avoid overwhipping to keep the frosting light and spreadable.
4 oz (113 g) cream cheese, ⅓ cup (40 g) confectioners' sugar, 1 tsp (5 ml) vanilla extract, 1 cup (240 ml) heavy whipping cream
Spread the frosting evenly over the chilled cake. Top with sliced fresh strawberries if desired.
fresh strawberries