Step 1: Preheat your oven to 350°F (175°C). Spread the walnuts on a baking sheet and toast them for about 8-10 minutes until fragrant.
Step 2: In a food processor, combine the toasted walnuts, rolled oats, black beans, diced onion, tomato paste, tamari, vegan Worcestershire sauce, Dijon mustard, onion powder, ground cumin, garlic powder, and smoked paprika. Pulse until well combined but still textured.
Step 3: Transfer the mixture to a mixing bowl and form it into burger patties. You should make about 6 patties.
Step 4: Line a baking sheet with parchment paper, place the patties on it, and bake for 20-25 minutes, flipping halfway through.
Step 5: Toast your buns, spread BBQ sauce on the bottom bun, add the burger patty, and top with lettuce, onion, tomato, and other toppings. Finish with the top bun and serve!