Preheat the oven to 350 degrees F (175 degrees C).

Mix barbecue sauce, pineapple, garlic powder, and chili powder together in a bowl.

Lay chicken legs in a 9x13-inch baking dish. Pour barbecue sauce mixture on top, making sure to coat all of the chicken. Cover with aluminum foil.

Bake in the preheated oven for 1 hour.

Remove chicken from the oven and let cool 1 hour.

Preheat an outdoor grill for medium heat and lightly oil the grate.

Place baked chicken on the hot grill and cook until browned on each side, 10 to 15 minutes.