Preheat oven to 350 degrees.
In a medium bowl, combine the rice flour with the baking soda.
Mash the banana.
Peel and finely chop the apple.
Melt the coconut oil.
In another bowl, mix together the egg, applesauce, mashed banana, coconut oil and chopped apple.
Add the dry ingredients to the wet ingredients and mix well.
If the dough seems a little dry or if all of the dry ingredients don’t get incorporated, add a small amount of water to the batter and continue mixing.
Place the dough into silicone or greased metal donut trays.
Bake at 350 degrees for 20 minutes.
Transfer the dog donuts to a wire rack to cool once baked.