Create the rub: In a small bowl, combine 2 tablespoons brown sugar, minced garlic, paprika, salt, black pepper, and cayenne (if using). Mash together to form a paste. You can use a mortar and pestle for best results.

Prepare the chicken: Place chicken pieces in a large resealable plastic bag. Add the spice paste, seal the bag, and massage to evenly coat all pieces. For best flavor, refrigerate and marinate for at least 1 hour, though overnight is ideal.

Make the BBQ sauce: While the chicken marinates, combine all sauce ingredients in a small saucepan over medium heat. Bring to a simmer, then reduce heat to low and cook for 15 minutes, stirring occasionally until slightly thickened. Let cool to room temperature.

Prepare the grill: Preheat your grill to medium heat (about 375°F). Oil the grates to prevent sticking.

Start grilling: Place the marinated chicken pieces on the grill, skin side down. Cook for 5-7 minutes until you have nice grill marks.

Flip and baste: Turn the chicken over and begin brushing with your homemade BBQ sauce. Continue grilling and turning occasionally, basting with more sauce each time.

Check for doneness: Cook until the internal temperature reaches 165°F for breasts and 175°F for thighs and drumsticks, about 25-35 minutes total depending on size.

Final touches: During the last 5 minutes of grilling, brush with a final coat of BBQ sauce to create a sticky, caramelized glaze.

Rest and serve: Remove chicken from the grill and let rest for 5-10 minutes before serving. This allows the juices to redistribute for maximum tenderness.