Preheat the oven to 325°F and line a large baking sheet with parchment paper.
Transfer the drained, rinsed, and dried beans to the prepared baking sheet in an even layer. Transfer to the oven and bake for 15 minutes. Remove the beans from the oven and set aside. Turn oven temperature up to 375℉
Add the olive oil to a large skillet set over medium heat. Add the onions and bell pepper and cook for 5-7 minutes or until softened. Add the garlic and cook for another two minutes, stirring continuously, until fragrant. Remove from heat.
Transfer the softened veggies to a large mixing bowl and allow it to cool to room temperature before adding the garlic powder, smoked paprika, chipotle chili powder, cumin, breadcrumbs, eggs, ketchup, Worcestershire Sauce, salt, and black pepper.
Mash everything together using a potato masher, then add the black beans and mash again, leaving some "big" chunks of beans.
Use your hands to form patties from the bean mixture - each pattie will be a little more than 1/3 of a cup and transfer to a large baking sheet lined with parchment paper.
Bake for 15 minutes, then turn the patties over carefully and bake for another 10 minutes.
As the burgers are baking, prepare the Sriracha mayonnaise. Add the mayonnaise, Sriracha, and lemon juice to a small bowl with a little salt and pepper and mix together with a small whisk.
Remove the black bean burgers from the oven and place on a hamburger bun. Top with the sriracha mayonnaise and dress with your favorite toppings.