Here's Why You Shouldn't Count Calories, According to a Registered Nurse & Healthy Banana Bread for One, 120 calories With only a few simple ingredients, you can make banana bread in the microwave in a matter of minutes or in a baking dish in the oven. Ingredients: 1/2 small banana, mashed 1 large egg white 2 tablespoons peanut flour (or oat flour* or protein powder) 1 teaspoon sweetener that measures like sugar 1/2 teaspoon baking powder Pinch of ground cinnamon 1 tablespoon chopped walnuts