2Combine apples, 1/4 cup rice flour, white sugar, and cinnamon in a bowl; transfer to an 8-inch baking dish.
3Mix brown sugar, butter, 1/2 cup rice flour, quinoa flakes, and rice flakes in the same bowl used for apple mixture. Sprinkle crumble topping over apple mixture and pat down gently.
4Bake in the preheated oven until apples are tender and topping is slightly browned, 35 minutes.