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

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

In another bowl, beat butter and sugar until light and fluffy. Add eggs one at a time, then mix in vanilla extract.

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

Divide batter evenly among the cupcake liners. Bake for 18-20 minutes, or until a toothpick comes out clean.

Let cupcakes cool completely before frosting.

For frosting, beat butter until fluffy. Gradually add powdered sugar, vanilla extract, milk, and salt. Adjust consistency as needed.

Pipe or spread frosting onto cooled cupcakes. Decorate with sprinkles if desired.