Start by preheating your oven to 350°F (175°C) and line a muffin tin with cupcake liners.
In a large bowl, combine the flour, baking powder, and salt.
In a separate bowl, cream the butter and sugar together until light and fluffy, about 2-3 minutes with an electric mixer on medium speed.
Add the eggs one at a time, beating well after each addition, then mix in the vanilla extract.
Alternately add the flour mixture and the milk to the butter mixture, starting and ending with the flour mixture. Mix each addition until just combined.
Fold in the sour cream until the batter is homogeneous.
Fill the cupcake liners two-thirds full with the batter.
Transfer the muffin tin to the oven and bake for 18-20 minutes, or until a toothpick inserted in the center comes out clean or with a few crumbs.
Allow the cupcakes to cool in the pan for a few minutes, then transfer to a wire rack to cool completely.
Once cooled, frost the cupcakes with vanilla frosting and top with sprinkles.