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

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

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

Stir in the limoncello and vanilla extract.

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

Gradually add the dry ingredients to the wet mixture, alternating with the milk, and mix until just combined.

Divide the batter evenly among the prepared cupcake liners.

Bake for 18-20 minutes or until a toothpick inserted into the center comes out clean.

Allow the cupcakes to cool completely before frosting.

In a mixing bowl, beat the softened butter until creamy.

Gradually add the powdered sugar, mixing until smooth.

Add the limoncello, lemon juice, and lemon zest, and mix until well combined and fluffy.

Frost the cooled cupcakes with the lemon frosting using a spatula or piping bag.