Disappearing Marshmallow Brownies

1/4 c Butter or margarine

3/4 c Flour

1/2 ts Vanilla

1 ts Baking powder

1 c Chocolate chips

1 Egg

1/4 ts Salt

13 c Brown sugar, packed

1 c Mini marshamallows

1/4 c Chopped nuts

Melt butterscotch chips and butter or margarine together over low heat, stirring constantly. Cool to lukewarm. Beat in egg. Combine dry ingredients including sugar, and stir into melted mixture. Fold in remaining stuff, sti just enough to combine (about 5 strokes). Spread in greased 9x9 inch pan and bake at 350 for 20-25 minutes.Do not overbake; center will be jiggly but firms up as it cools. "Happiness is like jam; you can't spread even a little without getting some of it on yourself."