01 - Set your grill or grill pan to medium-high heat and allow it to reach full temperature before cooking.
02 - In a small mixing bowl, combine the finely ground coffee, brown sugar, smoked paprika, chili powder, garlic powder, onion powder, and cayenne pepper. Stir until evenly blended and no clumps remain.
03 - Divide the ground beef into 4 equal portions, shaping each into a patty slightly wider than the burger buns to account for shrinkage. Season both sides of each patty with kosher salt and black pepper, then generously coat with the coffee rub mixture, pressing gently so the spices adhere to the meat.
04 - In a small saucepan over medium-low heat, combine the ketchup, apple cider vinegar, brown sugar, Worcestershire sauce, liquid smoke, smoked paprika, garlic powder, black pepper, and salt. Simmer for 5 to 7 minutes, stirring occasionally, until the sauce thickens and the flavors meld. Remove from heat and set aside.
05 - Place the seasoned patties on the hot grill and cook for 4 minutes on the first side. Flip each patty, add a slice of cheddar cheese if desired, and continue grilling for 3 to 4 additional minutes for medium doneness. During the final minute, place the burger buns cut-side down on the grill to toast.
06 - Spread a generous layer of smoky BBQ sauce on the bottom half of each toasted bun. Layer with lettuce, the coffee-rubbed burger patty, a tomato slice, red onion rings, pickle slices, and an additional drizzle of sauce. Cap with the top bun and serve immediately while hot.