Ingredients

1 cup butter
2 cups flour
1 tsp vanilla
1 cup firmly packed brown sugar
1 egg yolk
8 oz semi-sweet chocolate chips
1/2 cup finely chopped walnuts or pistachios

Directions

Preheat oven to 350F. Use a food processor or mixer to combine butter, flour, vanilla, brown sugar and egg yolk. Press into an ungreased 10×15-inch pan. Bake 15 minutes. Remove from the oven; sprinkle with chips. Let stand several minutes to melt the chocolate; spread chocolate evenly over the surface. Sprinkle with nuts. Cover with a piece of waxed paper; press gently to make nuts adhere. Score into bars while still warm; chill to harden chocolate.