Preheat oven to 350°F (175°C) and line cupcake pan.
Sift flour, baking powder, baking soda, and salt.
In a separate bowl, beat butter and sugar until fluffy.
Add vanilla, oil, and eggs one at a time.
Alternate adding dry ingredients and buttermilk until just combined.
Fill liners ⅔ full and bake 15 minutes or until a toothpick comes out clean.
Cool completely.
Beat butter, powdered sugar, vanilla, and milk until light and fluffy, adjusting milk for consistency.
Spread or pipe frosting onto cooled cupcakes.
Add sprinkles if desired.
