Margarita Cupcakes
Yield: about 24 cupcakes

Ingredients:
For the cupcakes:
3 cups all-purpose flour
1 tbsp. baking powder
1 cup (2 sticks) unsalted butter, at room temperature
2 cups sugar
4 large eggs, at room temperature
3 limes, zested and juiced (set about 1T zest aside for sugar topping)
½ tsp. vanilla extract
1 cup buttermilk
1 cup tequila (I used Patrone b/c it's clear)

Directions: 
To make the cupcakes, preheat the oven to 325˚ F. Line two cupcake pans with paper liners. In a medium bowl, combine the flour and baking powder; stir with a fork to blend. In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and sugar on medium-high speed until light and fluffy, 3-5 minutes. Blend in the eggs one at a time, mixing well after each addition and scraping down the sides of the bowl as needed. Beat in the lime zest, lime juice, vanilla and tequila. With the mixer on low speed, mix in the dry ingredients in three additions alternating with the buttermilk, beginning and ending with the dry ingredients. Beat each addition just until incorporated.  

Notes:  The batter  is very thin, so these took like 20min to cook at altitude.  Also b/c I'm at altitude, I added a couple extra tablespoons of flower.

For the Cream Cheese Frosting:
(Makes enough icing for about 24 cupcakes)

1/2 pound cream cheese, softened
1 stick butter, softened (or white shortening)
5-6 teaspoons lime juice (to taste)
2 - 2 1/2 cups sifted confectioners' sugar

In a large mixing bowl, beat the cream cheese, butter (shortening) and lime juice together until smooth.
Add the sugar and on low speed, beat until incorporated. Increase the speed to high and mix until very light and fluffy.

NOTE:
Use lime juice to taste and extra confectioners' sugar to get the consistency you want.

Sugar Topping
Take about 1 tablespoon of the lime zest from the batter recipe and combine it with several tablespoons of large crystal sugar.  Mix to incorporate.