For the cupcakes:
3 cups flour
1 tablespoon baking powder
½ teaspoon salt
1 cup (2 sticks) unsalted butter, at room temperature
2 cups sugar
4 eggs, at room temperature
1 cup buttermilk
3 limes, zested and juiced
½ teaspoon vanilla
2 tablespoons + ¼ cup tequila
For the frosting:
1½ cups diced strawberries
4 egg whites
1½ cups sugar
Generous pinch of salt
1½ cups (3 sticks) unsalted butter, cut into tablespoons, at room temperature
3-4 tablespoons lime juice
2-3 tablespoons tequila
Coarse salt, lime wedges and/or strawberry slices, for garnishing
Heat the oven to 325º and line two cupcake tins with liners. Whisk together the flour, baking powder and salt in a medium bowl and set aside.
In the bowl of an electric mixer fitted with the paddle attachment, beat the butter and sugar together at medium-high speed for 3-4 minutes, or until light and fluffy. Add the eggs one at a time, beating well after each addition, and scrape the sides and bottom of the bowl as needed.
Combine the buttermilk, lime zest and juice, vanilla and 2 tablespoons of the tequila in a 2 cup measuring cup. With the mixer on low speed, alternately add the dry and wet ingredients in 2-3 batches, starting and ending with the flour. Mix until just incorporated.
Divide the batter evenly among the prepared tins. Bake for 18-24 minutes, or until a toothpick inserted in the center comes out with a few crumbs and the top springs back when touched lightly. Cool the cupcakes in the tins for 5 minutes. Transfer to a wire rack and brush the tops with the remaining ¼ cup tequila and cool completely before frosting.
To make the frosting, puree the strawberries in a food processor and set aside. Combine the egg whites, sugar and salt in the bowl of a stand mixer set over a small saucepan of simmering water. Whisk constantly by hand until the sugar has dissolved. Test by rubbing the mixture between your fingers; you shouldn’t feel any grittiness.
Attach the bowl to the stand mixer fitted with the whisk attachment. Begin mixing on low speed and gradually increase to high and whip until stiff peaks form. Continue mixing until the mixture is completely cool (test by feeling the bottom of the bowl) and light, fluffy and glossy. This should take about 10 minutes but may take longer.
Replace the whisk attachment with the paddle attachment. Set the mixer to medium-low and add the butter, 2 tablespoons at a time, mixing well between each addition. Once all the butter has been incorporated, increase to medium speed and beat until fluffy. Gradually add the strawberry puree and lime juice and tequila, and mix to combine.
Frost cupcakes as desired and sprinkle with coarse salt. Garnish with lime wedges and/or strawberry slices, if desired.