Preheat the oven to 350°F and line a cupcake pan with liners.

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

In a large bowl, beat the butter and sugar until light and fluffy. Mix in the oil and vanilla extract.

Add eggs one at a time, beating well after each addition.

Alternate adding the dry ingredients and milk to the wet mixture, beginning and ending with dry ingredients. Mix until just combined.

Divide batter evenly among cupcake liners, filling each about 2/3 full.

Bake for 15-18 minutes or until a toothpick inserted in the center comes out clean.

Cool cupcakes in the pan for 5 minutes, then transfer to a wire rack to cool completely.

Prepare vanilla buttercream and frost cooled cupcakes.