Gluten Free Crumb Crust recipe: Replace Walnuts! - 1 cup brown rice flour, 1/2 cup ground walnuts, 3 tablespoons thawed apple juice concentrate, 2 tablespoons olive oil. Directions: In a small bowl, combine all ingredients. Press onto the bottom and up the sides of a 9-in. pie plate coated with cooking spray. Bake at 375° for 10-14 minutes or until set. Cool on a wire rack.