Step 1

Preheat oven to 350F.

Step 2

Grease and sprinkle with flour a 9-x-13 inch cake pan.

Step 3

Prepare white cake mix according to box instructions. Pour batter into the prepared pan and bake for about 25-30 minutes, or until a toothpick inserted in the center comes out clean. Let cool for 10 minutes and using the bottom of a wooden spoon, poke holes all over the cake, 1 inch apart.

Step 4

In a medium, microwave-safe bowl, combine white chocolate chips and sweetened condensed milk. Heat in the microwave until hot for about 1 minute, stir and heat for 30 seconds or more if needed. Stir until fully combined, smooth, and shiny.

Step 5

Stir in the strawberry gelatin and mix into the warm water. Make sure it dissolves, otherwise it will be gritty. Stir the strawberry mixture into the condensed milk mixture until fully combined and smooth.

Step 6

Pour the strawberry chocolate mixture all over the cake and using a spatula spread it evenly into the holes.

Step 7

Let the cake cool completely and refrigerate for about one hour.

Step 8

Top the cake with the strawberry pie filling if using.

Step 9

In a large bowl, beat heavy cream, sugar, and vanilla extract until stiff peaks form.

Step 10

Using a spoon, scoop the whipped cream all over the cake and spread it with a spatula.

Step 11

Garnish the cake with sliced strawberries.

Step 12

Refrigerate the cake for at least 8 hours or better overnight before serving.