01 - In a small bowl, combine the finely ground coffee, brown sugar, smoked paprika, ground cumin, garlic powder, onion powder, sea salt, black pepper, and cayenne pepper. Mix thoroughly until all spices are evenly distributed.
02 - Divide the ground beef into 4 equal portions, about 6 oz each. Gently shape each portion into a patty, making a slight indentation in the center to prevent puffing. Season both sides with kosher salt and freshly ground black pepper.
03 - Generously coat both sides of each patty with the coffee rub mixture, pressing gently to adhere. Set the patties aside at room temperature while preparing the sauce.
04 - In a saucepan over medium heat, combine the ketchup, apple cider vinegar, brown sugar, Worcestershire sauce, smoked paprika, garlic powder, onion powder, black pepper, salt, and liquid smoke if using. Stir well and simmer for 8 to 10 minutes, stirring occasionally, until the sauce has slightly thickened. Remove from heat and set aside.
05 - Preheat a grill or grill pan to medium-high heat, approximately 400°F. Lightly oil the grates to prevent sticking.
06 - Place the seasoned patties on the hot grill. Cook for 4 to 5 minutes per side for medium doneness, or adjust time to your preferred level. During the last minute of cooking, top each patty with a slice of sharp cheddar cheese if desired, and close the grill lid to allow the cheese to melt.
07 - Place the buns cut-side down on the grill for 1 to 2 minutes until golden brown and lightly crispy. Remove and set aside.
08 - Layer lettuce leaves, tomato slices, and red onion rings on the bottom buns. Place each coffee-rubbed patty on top, drizzle generously with the smoky BBQ sauce, and add dill pickle slices. Cap with the top buns and serve immediately.