Preheat the oven to 350°F (175°C) and line a cupcake pan with paper liners.

In a bowl, cream together the softened butter and granulated sugar until light and fluffy.

Add the eggs, one at a time, beating well after each addition.

Mix in the limoncello, vanilla extract, and milk.

In another bowl, whisk together the flour, baking powder, and salt.

Gradually add the dry ingredients to the wet mixture, stirring until just combined.

Divide the batter evenly among the cupcake liners.

Bake for 20 minutes or until a toothpick inserted into the center comes out clean. Allow to cool.

For the frosting, beat together the softened butter and powdered sugar until smooth and creamy.

Add the limoncello, lemon juice, and lemon zest, mixing until combined.

Once the cupcakes are cool, frost them with the lemon frosting.