Chocolate Peanut Butter Cupcakes

Ingredients

• 3/4 cup all purpose flour
• 1/3 cup cocoa powder
• 3/4 teaspoon baking soda
• 1/2 teaspoon salt
• 1/2 cup plus 2 tablespoons granulated sugar
• 1/2 cup buttermilk
• 1/3 cup vegetable oil
• 1 large egg
• 1 teaspoon pure vanilla extract
• 1/2 cup granulated sugar
• 2 large egg whites
• 1/8 teaspoon salt
• 12 tablespoons softened unsalted butter, cut into 1/2-inch pieces
• 1 cup peanut butter
• 2 teaspoons pure vanilla extract
• 8 ounces semi-sweet chocolate, finely chopped
• 1 1/2 tablespoons vegetable oil