Disappearing Marshmallow Brownies
["1/2 c. butterscotch or peanut butter morsels", "1/4 c. margarine", "3/4 c. flour", "1/3 c. brown sugar, packed", "1 tsp. baking powder", "1/4 tsp. salt", "1/2 tsp. vanilla", "1 egg", "1 c. miniature marshmallows", "1 c. semi-sweet chocolate morsels", "1/4 c. chopped nuts"]
["Preheat oven to 350\u00b0.", "Grease an 8 or 9-inch square pan.", "In a 3-quart heavy saucepan, melt margarine and butterscotch morsels. Stir constantly.", "Remove from heat and cool to lukewarm.", "Add next 6 ingredients to mixture in saucepan, stirring well.", "Fold remaining ingredients into saucepan.", "Spread into pregreased pan. Bake for 25 minutes.", "Do not overbake.", "(Batter will still be jiggly.)", "Cool and then cut into squares."]
["butterscotch", "margarine", "flour", "brown sugar", "baking powder", "salt", "vanilla", "egg", "marshmallows", "semi-sweet chocolate morsels", "nuts"]