1. Preheat oven to 350 degrees.
2. Whisk together flour, sugar, baking soda and baking powder in a large mixing bowl.
3. Add butter, egg white, egg, vanilla, mashed bananas and milk and mix on medium speed just until smooth. Do not over mix.
4. Fill cupcake liners a little more than half way.
5. Bake 18-20 minutes.
6. Allow to cool for 1 minute, then remove to cooling rack to finish cooling.
DULCE DE LECHE ICING
1. Combine butter and shortening and mix until smooth.
2. Add 2 cups of powdered sugar and mix until smooth.
3. Add dulce de leche and mix until smooth.
4. Add remaining powdered sugar and mix until smooth.
5. Add water or milk, if needed, until desired consistency is reached.
6. Spread a thin layer of dulce de leche on top of each cupcake.
6. Top cupcakes with icing and banana chips, if desired.