1. Cook spaghetti according to package directions and drain.
2. While spaghetti cooks, heat a large skillet over medium-high heat. Add oil and saute garlic, onion, and pepper until golden (3-5 minutes).
3. Add the water and broccoli, and cook until broccoli is tender (3-5 minutes).
4. Whisk together chili powder, peanuts, barbecue sauce, and peanut butter. Stir into broccoli. Heat briefly and serve over spaghetti.