To prevent banana milk from darkening, add a little fresh lemon juice.Variations:-Berry: add 1/4 cup strawberries, raspberries, blueberries, or blackberries and omit cinnamon, if desired.-Peanut butter + chocolate: add 2-3 teaspoons natural peanut butter (or 1 tablespoon peanuts) and 1-2 teaspoons cacao powder.