Thai peanut popcorn

12 cups1/4 cup butter or margarine 1 tablespoon soy sauce 1/8 teaspoon dried red pepper flakes 1/2 cup chunky style peanut butter 1/8 teaspoon garlic powder 12 cups popped cornIn a heavy saucepan, melt butter over medium heat. Add remaining ingredients except popcorn. Cook, stirring constantly, until smooth. Pour over popcorn, tossing to coat evenly. Serve at once.