01 - 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.
02 - Divide the ground beef into 4 equal portions, roughly 6 oz each. Gently shape each portion into a patty about 1/2 inch thick and slightly wider than the burger buns to account for shrinkage. Season both sides of each patty with kosher salt, black pepper, and a generous coating of the coffee rub, pressing the seasoning gently into the meat to adhere.
03 - 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. Stir to combine and bring to a gentle simmer. Cook for 5 to 7 minutes, stirring occasionally, until the sauce thickens and coats the back of a spoon. Remove from heat and set aside.
04 - Preheat an outdoor grill or grill pan to medium-high heat, approximately 400°F. Clean and lightly oil the grates to prevent sticking.
05 - Place the seasoned patties onto the hot grill. Cook for 4 minutes without disturbing to develop a charred crust. Flip the patties, top each with a slice of cheddar cheese if desired, and continue grilling for 3 to 4 additional minutes for medium doneness or until the internal temperature reaches 160°F. During the final minute, place the burger buns cut-side down on the grill to toast until golden.
06 - Spread a generous layer of smoky BBQ sauce on the bottom half of each toasted bun. Layer with a lettuce leaf, the coffee-rubbed burger patty, a tomato slice, a few red onion rings, and dill pickle chips. Drizzle additional BBQ sauce over the top if desired, then cap with the upper bun. Serve immediately while hot.