Mix rice flour, sugar, baking soda, and xanthan gum in a large bowl.
Then, in a large measuring cup, combine the oil and bananas.
Add oil/banana mixture into the bowl with dry ingredients and add about 2 Tbsp of orange juice or slightly more until the mixture is moist.
Put into muffin tins or 8" cake pan bake for about 25-30 minutes (longer for cake) at 350 ° until golden brown.
Optional Crumble Topping:
To make the crumble topping, keep about 1 Tbsp of the batter out. To that add about 1/4 c of quick oats, some sugar and some cinnamon. If it's too dry, add a little oil or OJ. Stir that together and place it lightly on top of the cake batter- don't tamp it down, just let it lay loosely. The texture and flavor is a nice touch, and it looks pretty.
Notes
This keeps very well and can be frozen. It might make a nice treat for those of you in need of breakfast foods. You can bulk it up by using different bran flours, or adding a protein powder.
Substitutions
If you cannot use orange juice, the original leavening for this cake was 1 tsp baking soda plus 1/4 tsp unbuffered vitamin C crystals and apple juice in place of the orange juice. If you don't have vitamin C crystals available, the orange juice is enough to activate the baking soda.
Gluten: Gluten is a protein found in specific grains (wheat, spelt, kamut, barley, rye). Other grains are naturally gluten-free but may have cross-contact with gluten-containing grains. Look for certified gluten-free products if you need to avoid gluten. Find out more about wheat and gluten substitutions.