1 c. butter
1 c. brown sugar
1 egg yolk
1 tsp. vanilla
2 c. flour
2 c. chocolate chips
1/2 c. chopped nuts

Cream butter and brown sugar. Add egg yolk, vanilla and flour; blend. Spread evenly in a lightly greased 9 x 13-inch pan.

Bake at 350°F for 15 to 20 minutes (until lightly brown). Remove from oven. Immediately sprinkle chocolate chips on top and set back in oven for 2 minutes. Remove and spread chocolate over bars immediately. Sprinkle with chopped nuts. Cool and cut.