1 c. (2 sticks) butter, softened
1 c. firmly packed light brown sugar
1 egg yolk
1 tsp. vanilla
2 1/4 c. sifted all-purpose flour
1 pkg. (12 oz.) semi-sweet chocolate bits
1 c. coarsely chopped walnuts or pecans

1. Preheat oven to 350 degrees. Grease a 9 x 13 inch pan.

2. Beat butter, sugar, egg yolk and vanilla in large bowl until moist and crumbly; stir in flour until blended, press batter into prepared pan.

3. Bake for 25 minutes. Remove from oven and sprinkle chocolate pieces over top. BAke 3-4 minutes until chocolate is melted. Spread with metal spatula. Sprinkle with nuts pressing down into chocolate.