Vanilla Cupcakes with Creamy Vanilla Buttercream

Preheat oven to 350 °. To prepare cupcakes, weigh or lightly spoon flour into a dry measuring cup; level with a knife. Combine flour, baking powder, and salt. Beat oil, egg, and egg white with a mixer at medium speed until combined. Add granulated sugar; beat until thick and pale. Add flour mixture and buttermilk alternately to sugar mixture, beginning and ending with flour mixture; mix after each addition. Stir in 2 teaspoons vanilla. Place 12 paper or foil muffin cup liners in muffin cups; coat liners with cooking spray. Spoon batter into cups. Bake at 350 ° for 20 to 22 minutes or until tops of cupcakes spring back when pressed in center (they will not be brown.) Cool in pan 10 minutes on a wire rack; remove from pan. Cool completely on a wire rack. To prepare buttercream frosting, place butter in a bowl; beat with a mixer at medium speed until light and fluffy. Add powdered sugar; beat at low speed until blended. Add half-and-half, 1 1/2 teaspoons vanilla, and dash of salt; beat at high speed until smooth and creamy. Top cupcakes with frosting. Sprinkle with sugar pearls, if desired.