01 -
Set your oven to 350°F. Spray a glass dish (9x13 size) lightly with nonstick spray. Push it to the side for now.
02 -
Combine the cake mix, eggs (or whites only), oil, and 1 cup of milk. Whisk everything together until you get a smooth batter.
03 -
Split the batter evenly across three bowls. Add a few drops of food coloring to each bowl, staring lightly and building up to get the color you want.
04 -
Spoon the colored batter in big dollops across the sprayed pan, one color at a time. When it's all in, lightly swirl with a knife (but not too much—you don't want the colors blending too much).
05 -
Put the dish in the oven and bake for 25 to 30 minutes. It’s done when a toothpick stuck in the middle mostly comes out clean, with just a couple crumbs sticking. Let the cake cool off completely.
06 -
Once the cake has mostly cooled, grab the handle of a wooden spoon or use a dowel. Press into the cake and make holes about 2/3 into the cake’s depth, spacing them roughly an inch apart.
07 -
Stir the pudding mix and the remaining 2 cups of milk together. Whisk for a minute or two, stopping once it thickens just a little. Pour evenly over the cake and spread it out, letting some pudding press into the holes.
08 -
Pop the cake into the fridge for half an hour so the pudding sets. Then spread the Cool Whip on top, and sprinkle some candies or sprinkles over everything.