Good-Cooking - S'more Cupcakes

Ingredients

• 1 cup fine graham cracker crumbs
• 1/2 cup sifted flour
• 1 1/2 teaspoons baking powder
• Pinch of salt
• 1/4 cup butter or margarine (at room temperature)*
• 1/4 cup shortening (at room temperature)
• 1 cup granulated sugar
• 2 eggs plus 1 egg white**
• 1/2 teaspoon vanilla extract
• About 18 marshmallows, each cut in half, divided
• About 4 plain milk chocolate candy bars, unwrapped, broken into individual squares and divided