Preheat oven to 350F.In a small bowl, add the chopped apple, 1T. brown rice flour, an ½t. cinnamon. Mix until coated, set aside.In a medium bowl, mash the bananas, and add the remaining wet ingredients. Stir until combined.Add the dry ingredients. Stir until just incorporated. Fold in cinnamon coated apple chunks.Fill evenly a 12 cup non-stick muffin tin.Bake until a toothpick comes out clean, about 30-40 minutes.Let cool. Use a knife to release the muffins from the tins.