PLACE barbecue sauce, 3/4 cup of the peanuts, the crushed red pepper and broth in blender; cover. Blend until smooth. Set aside.
HEAT 1 tsp. of the oil in large nonstick skillet on medium-high heat. Add chicken; cook 5 min. or until cooked through, stirring occasionally. Remove from skillet; keep warm. Add remaining 1 tsp. oil to skillet. Add onions and red peppers; cook 5 min. or until crisp-tender.
MEANWHILE, cook spaghetti as directed on package. Drain spaghetti; add immediately to skillet with chicken. Remove from heat; toss with peanut sauce to coat completely. Sprinkle with cilantro. Serve topped with remaining 1/4 cup peanuts, chopped.