01 -
Turn your oven to 325°F and line a 9x13 pan with parchment or non-stick foil. Spray the lining with a good amount of baking spray.
02 -
Use a big bowl to mix together the cake mix, melted butter, one egg, and 2/3 cup of milk. Stir well—it’ll be thick, like brownie batter. Split this batter into 6 small bowls equally.
03 -
Mix food coloring into the batter in each bowl to get pink, orange, yellow, green, blue, and purple. Scoop out 1 tablespoon of each colored batter and save it for later.
04 -
Spoon out teaspoons of each color randomly into the bottom of the prepared pan. Switch up the colors as much as possible. Gently flatten the surface with slightly wet hands once the batter is used up.
05 -
Stir 1 1/2 teaspoons of milk into each of the reserved tablespoons of batter. This thins them out, making them easier to swirl on top.
06 -
Beat the softened cream cheese and sugar until smooth and fluffy. Mix in the egg and vanilla until it’s all blended. Pour this over the rainbow base in the pan.
07 -
Drizzle the thinned colored batter across the cheesecake layer. Grab a fork or knife and gently swirl the colors together for a fun, marbled look.
08 -
Bake uncovered for about 20 minutes. Then cover the pan with foil to keep the colors from darkening. Bake for another 14-20 minutes. It’ll still jiggle a bit in the middle but will set as it cools.
09 -
Let the pan sit at room temperature for an hour to cool, then chill in the fridge for at least 2 hours. Slice into 24 squares and keep any leftover bars in the fridge.