Coat an unheated 12-inch nonstick skillet with nonstick cooking spray. Place over medium heat. Add onion and cook for 3 to 4 minutes or until tender. Add sweet peppers, garlic, chili powder, cumin, and ground red pepper; cook for 1 minute more.
Add turkey. Cook for 4 to 5 minutes or until turkey is no longer pink, stirring occasionally.
Stir in undrained tomatoes, cilantro, salt, crushed red pepper, and black pepper. Bring to boiling; reduce heat. Simmer, uncovered, over medium heat about 15 minutes or until sauce is of desired consistency.
Meanwhile, prepare spaghetti according to package directions. Drain.
Spoon sauce over spaghetti. Garnish with cilantro sprigs and cheese, if you like. Makes 8 servings.