Heat oven to 350 degrees. Grease bottom and sides of 9x13 pan.

1 c. butterscotch pieces (one 6 oz. pkg.)
1/2 c. butter
1 1/2 c. flour
2/3 c. brown sugar
2 tsp. baking powder
1/2 tsp. salt
1 tsp. vanilla
2 eggs
2 c. marshmallows
2 c. semi-sweet chocolate chips (one 12 oz. pkg.)
1/2 c. chopped nuts

Melt butterscotch pieces and butter in heavy saucepan over medium heat, stirring constantly. Remove and cool to lukewarm. Add flour, brown sugar, baking powder, salt, vanilla, and eggs to chips, and nuts just until combined. About 5 strokes. Bake 20 to 25 minutes. Check at 15 minutes. Do not overbake. Center will be jiggly, but becomes firm when cooled. Cut when completely cooled. Makes 2 to 3 dozen bars.