Sauté first 4 ingredients in hot olive oil in a large nonstick skillet over medium-high heat 8 minutes or until onion is tender.
Mash black beans and pinto beans in a large bowl; stir in onion mixture, salsa, and next 4 ingredients. Cover and chill 30 minutes.
Shape mixture into 8 patties. Place on an aluminum foil-lined baking sheet coated with cooking spray. Coat patties evenly with cooking spray. Chill 30 minutes.
Bake at 400° for 15 minutes or until browned and thoroughly heated.
Spread Adobo Mayonnaise on bottom halves of buns. Top with lettuce, tomato, patties, salsa, and top halves of buns.