Line a 13x9x2-inch baking pan with foil. In prepared pan combine cereal, wheat biscuits, and peanuts; set aside. In a small bowl combine honey mustard, butter, Worcestershire sauce, garlic powder, and cayenne pepper. Drizzle over cereal and nut mixture in pan, tossing gently to coat.
Bake in a 300 degrees degree oven for 20 minutes, gently stirring after 10 minutes. Stir in popcorn. Use foil to remove baked mixture from pan; cool completely. Makes 7 cups.