Brownie Marshmallow Krispy Bars

1 package 19.8 ounces Duncan Hines Chewy Fudge Brownie Mix

1 package 10-1/2 ounces, miniature marshmallows

1 1/2 cups semi-sweet chocolate chips

1 cup JIF Creamy Peanut butter

1 tablespoon butter or margarine

1 1/2 cups crisp rice cereal

Preheat oven to 350°. Grease bottom of 13 x 9 inch pan. Prepare and bake brownies following package directions for basic recipe. Remove from oven. Sprinkle marshmallows on hot brownies. Return to oven. Bake for 3 minutes longer. Place chocolate chips, peanut butter and butter in medium saucepan. Cook over low heat, stirring constantly until chips are melted. Add rice cereal; mix well. Spread mixture over marshmallow layer. Refrigerate until chilled. Cut into bars.