Ingredients
3cupsall-purpose flour
1tbspbaking powder
½tspsalt
1cupunsalted butter,room temperature
2cupssugar
4large eggs,room temperature
3limes,zested and juiced
½tspvanilla extract
1cupbuttermilk
2cupssugar
8egg whites
1½cupsbutter,room temperature
2½tbsplime juice
2tbsptequila
Preparation
Preheat the oven to 325 degrees F. Line two cupcake pans with paper liners.
In a medium bowl, combine the flour, baking powder and salt, then 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 for 3 to 5 minutes, until light and fluffy.
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, and vanilla.
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.
Divide the batter between the prepared cupcake liners, filling each about ¾ full.
Bake 20 to 24 minutes, or until a toothpick inserted in the center comes out clean.
Let cool in the pan for 5 to 10 minutes, then transfer to a wire rack to cool completely.
If desired, brush the cooled cakes with tequila.
Combine the sugar, egg whites, and salt in a heatproof bowl set over a pot of simmering water.
Heat, whisking frequently, until the mixture reaches 160 degrees F and the sugar has dissolved.
Transfer the mixture to the bowl of a stand mixer fitted with the whisk attachment. Beat on medium-high speed for 8 minutes until stiff peaks form and the mixture has cooled to room temperature.
Reduce the speed to medium, then add the butter, 1 tablespoon at a time, adding more once each addition has been incorporated. If the frosting looks curdled, continue to beat on medium-high speed for 3 to 5 minutes until thick and smooth again.
Stir in the lime juice and tequila, then mix until fully incorporated and smooth.
Frost the cooled cupcakes with the buttercream, then garnish with lime zest and lime slices. Enjoy!
