Ingredients

• Crust:
• 1 1/4 cups white rice flour
• 1 cup confectioners' sugar
• 3/4 cup gluten-free oat flour (such as Bob's Red Mill®)
• 1 cup butter, softened
• Filling:
• 4 eggs
• 1 3/4 cups white sugar
• 1/4 cup white rice flour
• 1 teaspoon baking powder
• 1 lemon, juiced
• 1 teaspoon lemon zest (optional)

Instructions

1. Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13-inch baking dish.
2. Whisk 1 1/4 cup rice flour, confectioners' sugar, and oat flour together in a bowl. Mix butter into flour mixture until evenly combined; press into the bottom of the prepared baking dish.
3. Bake in the preheated oven until crust is golden brown, about 15 minutes.
4. Beat eggs together in a bowl until light and smooth. Combine white sugar, 1/4 cup rice flour, and baking powder together in a separate bowl; stir into beaten eggs until just combined. Stir lemon juice and lemon zest into egg mixture; pour over crust.
5. Bake in the preheated oven until filling is set, about 30 minutes. Cool completely before cutting into bars.