- 1 cup butter
- 1 cup packed brown sugar
- 1 egg yolk
- 2 cups sifted all-purpose flour
- 1 teaspoon vanilla extract
- 1 cup semisweet chocolate chips
- 1 cup chopped walnuts (optional)
- Cream together butter or margarine and brown sugar, packed Add 1 egg yolk, sifted flour, and vanilla. Batter will be stiff.
- Spread on a greased 13 x 9 inch cookie sheet. Bake at 375 degrees F (190 degrees C) for 12-15 minutes until golden brown.
- While still warm, add 1 cup semi-sweet chocolate chips to top of cookie until melted. Spread with knife until top is covered. Add chopped nuts, if desired. Let cool, then cut into squares.