Preheat your oven to 350°F (175°C). Prepare the white cake mix according to the package instructions, adding the necessary eggs, water, and oil.

Divide the batter evenly into four bowls, adding a few drops of different food coloring to each bowl. Stir until colors are vibrant, then set aside.

Pour spoonfuls of the colored batter into a greased 9x13 inch baking dish, alternating colors for a marbled effect. Use a toothpick to swirl colors together gently. Bake for 25-30 minutes until a toothpick comes out clean.

Allow it to cool for 10 minutes in the pan. Poke holes evenly across the top of the cake using a wooden spoon, about 1 inch apart.

In a medium bowl, whisk together the instant white chocolate pudding and 2 cups of cold milk until smooth. Pour the pudding mixture generously over the cooled cake, ensuring it fills the holes.

Cover the cake with plastic wrap and place in the refrigerator for at least one hour, ideally for 2 to 4 hours.

Make your whipped cream by beating heavy cream and powdered sugar until soft peaks form. Spread whipped cream over the top of the cake.