Fool-proof no-fat vegan banana bread

I couldn't find my family recipe for banana bread, so I decided to wing it. This turned out awesome. It's less like a traditional crumbly quick bread and more like a nice dense breakfast bread, but with all the delicious banana bread flavor and none of the fat. (Well, there's a negligible amount of fat in the banana itself, but not enough to count - less than a quarter of a gram per slice. And you do spray the pan. Still, I'm comfortable calling this 'no-fat'.)

Fool-proof no-fat banana bread

4 over-ripe bananas, mashed

2/3 cup sugar

1 cup white flour

1 cup whole wheat pastry flour

1 tsp baking powder

1/2 tsp salt 

1 tsp vanilla

4 tbsp water

Preheat oven to 350 degrees. Mash bananas and add wet ingredients. In a separate bowl, sift together dry ingredients. Slowly mix dry ingredients into wet. Spray a loaf pan with cooking spray and pour batter into pan. Bake 55 minutes or until golden brown and pulling away from the sides. Cool in pan on a wire rack for five minutes, then remove from pan (or cool completely in pan).