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

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

Beat in the eggs one at a time, then stir in the vanilla extract.

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

Gradually add the dry ingredients to the wet ingredients, alternating with the milk. Mix until just combined.

Fill each cupcake liner about 2/3 full with the batter.

Bake in the preheated oven for 20 minutes, or until a toothpick inserted into the center comes out clean.

Allow the cupcakes to cool completely before frosting.

For the frosting, beat together the softened butter and powdered sugar until well combined.

Stir in the milk and vanilla extract until the frosting is smooth and creamy.

Frost the cooled cupcakes as desired.