2Whisk together the flour, baking powder, and salt; set aside.
Cream butter with mixer until light and fluffy, slowly add sugar. Add egg and egg whites until blended.
Add half the flour mixture; mix until just blended. Add the milk and the extracts, mix until just blended. Slowly add remaining flour mixture.
3Pour evenly into paper-lined muffin tin.
Bake for approximately 25 minutes. Transfer to wire racks and let cupcakes cool before icing.
4To make icing, beat marshmallow creme, whipped topping, and 1/8 teaspoon peppermint extract together at high speed with an electric mixer for 1 to 2 minutes or until glossy and stiff peaks form.