Ingredients

The following ingredients have 12 Servings
  • 1 1/2 cups (213 grams) all-purpose flour
  • 1 1/2 teaspoon baking powder
  • 1/4 teaspoon salt
  • 1/2 cup (1 stick, 113 grams) unsalted butter (at room temperature)
  • 1 cup (198 grams) granulated sugar
  • 2 eggs (at room temperature)
  • 1 lime (zested and juiced)
  • 1 grapefruit (zested)
  • 2 tablespoons grapefruit juice
  • 1 tablespoon white or silver tequila
  • 1/4 teaspoon vanilla extract
  • 1/2 cup (120 milliliters) buttermilk
  • 1 tablespoon white or silver tequila
  • 1 cup (2 sticks, 226 grams) unsalted butter (at room temperature)
  • 3 cups (340 grams) powdered sugar
  • 1 tablespoon lime juice
  • 1 tablespoon grapefruit juice
  • 1 tablespoon white or silver tequila
  • pinch of coarse salt

Instruction

  • Preheat oven to 325 degrees F (160 C). Prepare a 12-cup muffin tin with paper liners and set aside.
  • In a medium bowl, whisk together the flour, baking powder, and salt; set aside.
  • Using an electric mixer on medium-high speed, beat the butter and sugar together until pale, light, and fluffy. Reduce speed to medium and add the eggs one at a time, mixing well after each addition.
  • Add the lime and grapefruit zest and juice, vanilla extract, and tequila. Scrape the sides of the bowl and mix until combined. (Don’t worry if the batter looks slightly curdled; it will come back together.)
  • Reduce the speed to low and add the dry ingredients in two batches, alternating with the buttermilk. Mix each addition just until incorporated, and use a spatula to give it one last stir by hand.
  • Divide the batter evenly between the muffin wells, and bake until the cupcakes are light golden brown and a skewer inserted in the center comes out with moist crumbs attached, about 25 minutes.
  • Allow cupcakes to cool in the pan for about 10 minutes, then remove to a cooling rack. Brush the cupcake tops with the 1 tablespoon of tequila, then set aside to cool completely before frosting.
  • To make the frosting, whip butter using an electric mixer on medium-high for 5 minutes. Reduce speed to low and gradually add the powdered sugar, scraping the sides of the bowl occasionally as you go. Add the lime and grapefruit juice, tequila, and salt, and beat on medium-high for 3-4 minutes, until frosting is smooth and fluffy. Frost cupcakes and garnish, if desired, with zest and small wedges from leftover limes or grapefruit.