Combine the peanut powder with the water until it thickens.
Add to the flour.
Add in the baking soda, salt, sugar, butter, and eggs.
Mix in the bananas, yogurt, and vanilla.
Spray a muffin tin with non-stick baking spray, then add in the batter to each tin, about half full. Note - The batter will be thick, spread it in evenly.
Top each muffin with a bit of oats.
This makes about 18 muffins.
Bake for 25-30 minutes or until when poked with a toothpick in the deepest part it comes out clean.
Remove the plan and let cool, then remove the muffins and serve.