Preheat oven to 350°F and line a cupcake pan with liners.
In a bowl, whisk together: flour, baking powder, and salt.
In a separate large bowl, beat butter, oil, and sugar until light and fluffy (about 2–3 minutes).
Add eggs one at a time, mixing well after each.
Mix in vanilla extract.
Add dry ingredients in two parts, alternating with milk and sour cream. Mix just until combined — don’t overmix!
Fill cupcake liners about 2/3 full.
Cupcake Bake Time: Bake at 350°F for 18–22 minutes
Centers should spring back lightly when touched
A toothpick should come out clean or with a few crumbs
Cool in the pan for 5 minutes, then transfer to a rack to cool completely before frosting.