01 - Preheat a grill or grill pan to medium-high heat, approximately 400°F.
02 - In a small mixing bowl, combine the ground coffee, brown sugar, smoked paprika, black pepper, kosher salt, garlic powder, onion powder, and cayenne pepper. Stir until evenly blended.
03 - Divide the ground beef into 4 equal portions and gently shape into patties, making a slight indentation in the center to prevent puffing. Generously coat both sides of each patty with the coffee rub, pressing gently so the seasoning adheres.
04 - In a small saucepan over medium heat, whisk together the ketchup, apple cider vinegar, brown sugar, Worcestershire sauce, smoked paprika, chipotle chili powder, garlic powder, onion powder, and salt. Bring to a gentle simmer and cook for 5 to 7 minutes, stirring occasionally, until the sauce thickens slightly. Remove from heat and set aside.
05 - Place the seasoned patties on the preheated grill. Cook for 4 to 5 minutes per side, or until the internal temperature reaches 160°F for medium doneness. If using cheese, place a slice on each patty during the final minute of grilling and close the lid to melt.
06 - Place the burger buns cut-side down on the grill and toast for 1 to 2 minutes until lightly golden.
07 - Spread a generous spoonful of smoky BBQ sauce on each bottom bun. Layer with lettuce, a grilled burger patty, tomato slice, red onion ring, and an extra drizzle of sauce if desired. Cap with the top bun and serve immediately.