- Crust:
- 1 cup white rice flour
- 3/4 cup butter
- 1/2 cup confectioners' sugar
- 1/4 cup potato starch
- 1/4 cup tapioca starch
- Topping:
- 3 cups finely chopped rhubarb
- 2 1/4 cups white sugar
- 3 eggs, well-beaten
- 1/3 cup white rice flour
- 1 teaspoon salt
- Preheat oven to 350 degrees F (175 degrees C).
- Mix 1 cup rice flour, butter, confectioners' sugar, potato starch, and tapioca starch together in a bowl until crumbly and evenly combined; press into a 9×13-inch baking dish.
- Bake in the preheated oven until crust is bubbling, about 18 minutes.
- Mix rhubarb, white sugar, eggs, 1/3 cup rice flour, and salt together in a bowl; spoon over crust.
- Bake in the oven until topping is bubbling, about 35 minutes.