1: Preheat the microwave and prepare your baking dish.
2: In a bowl, mix the egg whites and yogurt together.
3: Add lemon zest and baking powder to the mixture.
4: If desired, add sweetener to taste.
5: Stir in the oat or whole wheat flour until combined.
6: Pour the batter into the baking dish and microwave for the recommended time.
7: Let it cool before serving.
