1 c. butter
1/2 c. brown sugar
1/2 c. granulated sugar
1 lg. egg
2 tsp. vanilla
About 1 3/4 c. flour
1 1/2 c. (8 oz.) semi-sweet chocolate baking bits
1/2 c. roasted peanuts
2 c. miniature marshmallows

Beat butter and sugars until smooth. Add egg and vanilla. Beat. Add flour, beating slowly to mix. Butter and flour - dust a 12 inch pizza pan or a 10 x 15 inch rimmed baking pan. Pour mixture in pan and bake at 350 degrees until browned and firm in center, about 20 minutes.

Combine remaining ingredients and sprinkle over hot cookie. Bake about 15 minutes more. Let cool 10 minutes. Cut; serve warm. Store at room temperature up to 3 days.