1 1/2 c. butter, melted
1 1/2 c. brown sugar, packed
2 egg yolks
1 1/2 tsp. vanilla
3 c. flour
1/2 tsp. salt (optional)
16 oz. chocolate chips

Preheat oven to 350 degrees. Mix all ingredients except chocolate chips. Place dough onto a greased jelly roll pan (with sides). Evenly spread dough in pan. Bake 20 minutes or until golden brown. Cool cookie.

Melt chocolate chips. Pour and evenly spread melted chocolate chips over cookie. (OPTIONAL: Sprinkle with chopped nuts while chocolate is wet.) Cool cookie. Cut into squares. About 150 servings.