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 vanilla extract and milk.

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 in 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 well.

Add the milk and vanilla extract, and beat until the frosting is light and fluffy.

Frost the cooled cupcakes as desired.