1 stick (8 tablespoons) unsalted butter, melted, plus more for greasing the loaf pan
3/4 cup brown rice flour
1/2 cup tapioca flour
2/3 cup plus 1 tablespoon sugar
1 teaspoon baking powder
1/4 teaspoon baking soda
1/2 teaspoon ground cinnamon
1/2 teaspoon fine salt
2 large eggs, separated
1 teaspoon pure vanilla extract
3 very ripe bananas, mashed
When measuring flour, we spoon it into a dry measuring cup and level off the excess. (Scooping directly from the bag compacts the flour, resulting in dry baked goods.)