Snap off tough ends of asparagus. Cut asparagus into 1-inch pieces. Set aside.
Cook pasta according to package directions, omitting salt and fat. Add asparagus pieces to pasta during the last 2 minutes of cooking time. Add carrots during the last 30 seconds of cooking time.
Combine peanut butter and next 5 ingredients in a small saucepan. Cook over medium heat, stirring occasionally, until mixture comes to a boil. Remove from heat.
Drain pasta, and place in a large serving bowl. Stir in peanut sauce, tossing to coat. Top evenly with peanuts.