1 c. packed light brown sugar
1 c. butter, softened
1 egg yolk
1 tsp. vanilla extract
2 c. all-purpose flour
1/4 tsp. salt
1 3/4 c. (10 oz. pkg.) Hershey's premium milk chocolate or semi-sweet chocolate chunks
1/2 c. coarsely chopped pecans

Heat oven to 350 degrees. Grease 13 x 9 x 2 inch baking pan. In large mixer bowl combine brown sugar, butter, egg yolk and vanilla; blend in flour and salt. Press mixture into prepared pan. Bake 25-30 minutes or until light browned. Remove from oven; immediately sprinkle chocolate chunks on crust. Let stand until softened, about 5 minutes. Spread evenly over crust; sprinkle with pecans. Cool completely; cut into bars.