The batter was colored. Teal, pink, yellow, green, and lavendar. Lookie:
Despite my not-so-great picture, can you see all the layers of color? Tie Dye!
To make these, mix up your favorite white or yellow cake batter. Divide the batter between 5 or 6 bowls. Color the batter with paste food coloring to your preference (i.e. pastel or bright). Mix well!
Line a cupcake tin with cupcake liners. (If you use white, as I did, you'll be able to see the colored cake after baking!) Using a teaspoon, drop spoonsful of batter in each cupcake liner, one color directly on top of the other, filling the cupcake liners about 2/3 full. Tap the cupcake pan on your countertop to level out the batter. Bake according to your recipe directions.
You can apply this technique to full size cakes as well! Use a measuring cup to pour batter in the center of the pan, layering each color directly on top, in the center. The result is a super colorful and fun cake!!