How to Make It
Preheat oven to 350°.
To prepare cupcakes, weigh or lightly spoon flours and cornstarch into dry measuring cups; level with a knife. Combine flours, cornstarch, baking powder, and next 4 ingredients (through cinnamon) in a medium bowl; stir with a whisk.
Combine granulated sugar, banana, and canola oil in a large bowl; beat with a mixer at medium speed until smooth. Add eggs, 1 at a time, beating well after each addition. Beat in 1 teaspoon vanilla. Add flour mixture and 1/2 cup milk alternately to sugar mixture, beginning and ending with flour mixture.
Place 18 paper muffin cup liners in muffin cups; coat liners with cooking spray. Spoon batter into prepared cups. Bake at 350° for 24 minutes or until a wooden pick inserted in center comes out clean. Cool 5 minutes in pans on a wire rack; remove from pans. Cool completely on wire rack.
To prepare frosting, heat butter in a small saucepan over medium heat; cook 2 minutes or until browned, stirring constantly. Remove from heat; cool 5 minutes.
Place browned butter, powdered sugar, 2 tablespoons milk, and 1 teaspoon vanilla in a medium bowl; beat with a mixer at low speed until smooth. Spread frosting over cupcakes, and sprinkle with brickle chips.
Gluten-Free Baking; The Food Lover's Gluten-Free Cookbook