Heat oil over medium heat in a skillet. Once hot, add chopped onions and 1 tablespoon of adobo sauce (you can throw in a pepper if you'd like). Cook until onions are translucent, about 5-6 minutes. Then, add minced garlic and cook on low heat for 2 minutes. Remove heat.
Add beans, corn, spices, onions and garlic mixture, and salt and pepper to a bowl. Season to taste. Then, combine contents and roughly mash with potato masher or fork. Add oat flour and incorporate.
Cover bowl tightly with plastic wrap and refridgerate mixture for at least 30 minutes and up to 24 hours. The longer, the more firm the mixture.
Pre-heat oven to 350 degrees and line baking sheet with parchment paper. Shape burger mixture into 4-6 patties and place on baking sheet. Bake for 15 minutes, flipping once so that both sides of patties have browned. Alternatively, you can heat 1 tablespoon of oil in a pan and cook patties for 5-6 minutes, flipping once. Enjoy!
To make oat flour:
Add quick or old-fashioned oats to a blender or food processor. Pulse the oats until they turn into a fine powder.
On the chipotle peppers:
You can add more adobo sauce and/or chipotle peppers to the black bean mixture if you'd like, adjust to your taste. You can also reduce how much adobo is used when cooking the onions and garlic.