01 -
Preheat oven to 350°F. Lightly grease a 9x13 inch baking pan or line it with parchment paper to prevent sticking.
02 -
In a large bowl, mix funfetti cake mix, egg, melted butter, and heavy cream until smooth and fully incorporated.
03 -
Spread batter evenly into prepared pan. Bake for 20 to 25 minutes or until a toothpick inserted into the center comes out clean.
04 -
Remove from oven and allow bars to cool completely in pan to ensure frosting adheres properly.
05 -
Beat cream cheese and softened butter together in a large bowl until smooth and creamy using a mixer.
06 -
Gradually beat in powdered sugar, about half a cup at a time, mixing on medium speed until light and fluffy.
07 -
Add heavy cream and vanilla extract one tablespoon at a time, beating on high speed until frosting is light and spreadable.
08 -
Divide frosting into two bowls. Fold purple food coloring into one and blue food coloring into the other until desired shades are achieved.
09 -
Spread colored frostings alternately over cooled bars. Use a spoon or spatula to swirl colors together, creating a marbled effect.
10 -
Optionally sprinkle with sprinkles. Cut into bars and serve chilled or at room temperature.