POUR 1/4 cup of the dressing over chicken in medium bowl; toss to coat. Cover. Refrigerate 1 hour to marinate. Remove chicken from marinade; discard marinade.
MIX remaining 1/2 cup dressing, peanut butter, honey, soy sauce and crushed red pepper with wire whisk until well blended; set aside.
COOK and stir chicken in large skillet on medium-high heat 5 minutes. Add snap peas; cook and stir an additional 3 minutes or until chicken is cooked through. Remove skillet from heat. Add dressing mixture and spaghetti; toss lightly. Serve immediately. Or, cover and refrigerate until ready to serve.