Heat the olive oil in a large skillet over medium heat. Add the onion and garlic and cook until softened, about 5 minutes.
Add the bell peppers and jalapeno (if using) and cook for another 5 minutes.
Stir in the cumin, chili powder, smoked paprika and cayenne pepper (if using). Cook for 1 minute.
Add the black beans and pinto beans. Cook until heated through.
To assemble burritos: Place a few spoonfuls of bean mixture onto each tortilla. Top with desired toppings such as lettuce, tomatoes, cheese, salsa or avocado.