Add chickpeas, bananas, and rolled oats to a food processor. Pulse until smooth.
In a large mixing bowl, combine blended chickpea, banana, oat mixture with brown sugar, baking soda, cinnamon, salt, eggs, butter, and vanilla extract. Stir until well mixed.
Pour or spoon batter into silicone baking cups and arrange baking cups on a baking sheet. Bake in oven for 15-20 minutes, or until tops are golden-brown and a toothpick inserted in the center of the muffin comes out clean.
Notes
If you don't have a food processor, you can use a blender for the banana, chickpea, oat mixture. If you don't have either, you can mash the chickpeas and banana with a fork or potato masher. Note that the texture will not be as smooth.