Mix flour, sugar, baking powder, and salt; set aside. In a mixing bowl, whisk egg substitute, milk, oil, and vanilla extract. Slowly whisk in the dry ingredients, just until smooth. Add mashed bananas; whisk to integrate.
Spray preheated waffle iron with non-stick cooking spray. Pour mix onto hot waffle iron. Sprinkle waffle batter with about 1 tsp mini chocolate chips. Cook until golden brown. Serve hot.