Preheat the oven to 350 degrees. Spray 8-inch square pan w/ vegetable oil. Stir together the first 4 ingrdients and set them aside. Melt butter in saucepan. Stir in the sugar, add the egg, egg whites, vanilla and espresso. Beat w/ wooden spoon until well combined. Scrape mixture into prepared pan. Bake 20-25 minutes.
