1 c. butter (or half and half)
1 c. light brown sugar
1 tsp. vanilla
2 c. flour
1 egg yolk
1 pkg. semi-sweet chocolate bits (11-12 oz. pkg.)
Nuts, if desired

Cream butter, sugar and add vanilla. Add flour and egg yolk. Spread on cookie sheet (with sides) and bake for about 15 minutes at 350 degrees.