Preheat the oven to 350°F (175°C) and line a cupcake pan with 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 milk and vanilla extract.

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

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

Divide the batter evenly among the cupcake liners, filling each about 2/3 full.

Bake in the preheated oven 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 on low speed until combined.

Add the milk and vanilla extract, then beat on high speed until light and fluffy.

Frost the cooled cupcakes as desired.