For the baby cakes:

Preheat oven to 350°F.

A couple notes: I prefer to use flexible silicone mini muffin pans with no paper liners for this recipe, but you can also prepare metal mini muffin pans with paper liners. Also, I found that there are different-sized mini muffin pans out there, so your yield and baking time may vary a bit. The silicone pans I used yield a little bigger mini cupcake than others, which I also happen to like.

Whisk flour, baking powder, and salt in medium bowl and set aside. In a large bowl, beat butter until smooth. Add sugar and beat to blend. Beat in eggs 1 at a time, then the lime juice, lime peel, and food coloring. Batter may look curdled, but that’s just fine. Beat in the flour mixture alternately with the buttermilk, in 3 additions. Spoon batter into liners, about 2/3 full. Bake cupcakes until tester inserted into center comes out clean. This took about 20 minutes for me, but it will depend on the size of your tins, so pay close attention to your baking time. Cool 10 minutes and remove from pan. Cool completely before adding frosting.

For the frosting:

Beat all ingredients in a medium bowl until smooth. With a medium-large plain round tip, pipe frosting onto cooled cupcakes, or simply spread it on with a knife. Sprinkle a bit of fresh lime zest over tops, if desired.

Source: Heavily adapted from Bon Appetit, original recipe from Buttersweet Bakery in Atlanta.