Preheat oven to 350 degrees. Line 6 muffin cups with paper liners and set aside. (You can use either a 6-cup muffin tin or a 12-cup muffin tin. Both work!)
In a large bowl, add the flour, baking powder and salt. Mix together with a fork/whisk and set aside.
In another large bowl, beat the butter on high until smooth using a handheld or stand mixer. Add in the sugar and mix for 1-2 minutes, until the butter and sugar have fully come together. Add in the egg, lime juice, milk and tequila and mix for 30 seconds until combined.
With the mixer on low, slowly add in the dry ingredients by adding a little, mixing it in and then adding some more until the wet and dry ingredients have been combined.
Evenly pour the batter into the liners up to about 2/3 full and bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
Important: Remove the cupcakes from the oven and allow to cool completely before frosting.
For the frosting
In a large bowl, add the butter, cream cheese. Mix together until completely smooth using a handheld or stand mixer.
Add in the vanilla extract, lime juice, silver tequila and pinch of salt. Mix together for about 30 seconds, until combined.
With the mixer on low, slowly add in the powdered sugar by adding a little, mixing it in and then adding some more until the wet and dry ingredients have been combined.
Frost the cupcakes and garnish with some more lime zest and a slice of lime if desired.
Notes
The frosting makes 1.5 cups and is enough to cover 12 cupcakes.Recipe adapted from Inspired Home.