1 cup (2 sticks) butter
1 cup brown sugar, packed
1 egg yolk
1 tsp. vanilla
2 cups all-purpose flour
1/4 tsp. salt
3 to 4 milk chocolate bars (7 to 8 oz. each)
1/2 cup chopped nuts

Preheat oven to 350°F.

Mix butter, sugar, egg yolk and vanilla. Measure flour by sifting. Stir in flour and salt until dough is well blended. Spread in a rectangle about 13x10-inch on greased baking sheet, leaving about 1-inch all around edge of baking sheet.

Bake at 350°F for 20 to 25 minutes or until nicely browned.

Crust will be soft. Remove from oven. Immediately place separated squares of chocolate on top. Let stand until soft; spread evenly over entire surface. Sprinkle with nuts. Cut in small squares while warm.

Variation: For a softer cake-like cookie, spread dough in an oblong pan, 13 x 9 1/2 x 2-inch; bake at 350°F for 25 to 30 minutes.

Makes 6 to 7 dozen squares.