Want to know how to make these rainbow cupcakes, for St. Patrick's Day or otherwise? Head on over to food blog The Curvy Carrot for the recipe! She writes:
As far as the cake goes, use your favorite white cake recipe, divide the batter into several small bowls, and color each bowl with your desired food coloring gels. I decided to try a white cake recipe from King Arthur for this recipe, but, in all honesty, I will most likely go back to my favorite from Baking Illustrated (see the recipe here) because I like the spongy texture (and the more potent almond flavor.) better. And for the frosting? I was running low on vanilla extract, so I threw in some butter flavoring instead. Holy moly. If you want a buttery buttercream (and who doesn’t, really?), try this if you happen to have some on hand. It’ll knock your socks off.