Line a baking pan with parchment paper or coat with cooking spray.
Smash beans with a fork in a large bowl. Stop when they're halfway between whole beans and refried beans.
Add oats, brown rice, barbecue sauce, onion powder and salt. Mix with your hands until evenly combined.
Form into 12 patties. Let rest in the fridge for 20-30 min (see note).
Bake at 450 F for 8-10 min on each side, or until light brown and crispy.
Notes
Make-ahead directions: Make uncooked burgers up to 24 hours in advance. Refrigerate until ready to bake, then bake as usual. Make-ahead freezer directions: Double the batch, bake in advance, and freeze the patties in layers separated by wax paper. Warm in the microwave and serve as needed!
Recipe by Veggie Quest at https://www.veggie-quest.com/2017/12/easy-barbecue-black-bean-burgers-vegan-just-0-23-each/