01 - Preheat your grill or grill pan to medium-high heat, approximately 400°F (200°C). Clean and oil the grates to prevent sticking.
02 - In a small mixing bowl, whisk together the finely ground coffee, brown sugar, smoked paprika, chili powder, garlic powder, onion powder, and cayenne pepper until evenly combined.
03 - Divide the ground beef into 4 equal portions (about 170 g each). Gently shape each portion into a patty slightly wider than the buns, pressing a shallow dimple in the center to prevent puffing. Season both sides generously with kosher salt, black pepper, and the coffee rub, pressing the seasoning gently to adhere.
04 - In a small saucepan, combine the ketchup, apple cider vinegar, brown sugar, Worcestershire sauce, liquid smoke, smoked paprika, garlic powder, black pepper, and salt. Place over medium-low heat and simmer for 5–7 minutes, stirring occasionally, until the sauce thickens and coats the back of a spoon. Remove from heat and set aside.
05 - Place the seasoned patties on the hot grill. Cook for 4 minutes without moving, then flip. If using cheese, lay a slice of cheddar on each patty immediately after flipping. Grill for another 3–4 minutes for medium doneness (internal temperature of 160°F / 71°C). During the last minute, toast the buns cut-side down on the grill until lightly golden.
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 chips, and an additional drizzle of sauce. Cap with the top bun and serve immediately while hot.