Heat oven to 350 degrees. Lightly coat an 11x17 inch baking dish with cooking spray. Set aside.
Drain pineapple chunks and reserve 2 tablespoons of juice. To a large bowl add the drained beans, pineapple chunks, and chopped onion.
In a small bowl, mix BBQ sauce, reserved pineapple juice, ketchup, brown sugar, honey, whole grain mustard, garlic powder, salt, and pepper. Pour mixture over beans.
Mix all ingredient together then pour into prepared dish. Add bacon pieces to the top of the mixture. Cover with foil and bake for 30 minutes. Uncover beans and continue to cook for 20 minutes. Remove from the oven, and let sit for 5 minutes. Serve hot.