Mix box cake batter according to box instructions. Divide batter into three Thatsa® Bowls and add 3-4 drops of one food coloring per bowl. Place Silicone Muffin Form in UltraPro 3.5-Qt./3.3 L Lasagna Pan and scoop each color into each muffin cavity. Fill only halfway. Gently swirl with Silicone Spatula to create pattern.
Cook & decorate
Microwave for 3 minutes on high power or until toothpick inserted in center comes out clean. Let cool slightly before unmolding and repeat process with remaining batter.
Once completely cooled, decorate with frosting of choice, add sprinkles and serve.