Cream 1 cup butter until soft; gradually add 1 cup sugar, creaming until light and fluffy. Add 2 egg yolks and blend well. Gradually add 2 cups sifted flour and mix well. Then fold in 1 cup chopped walnuts.

Spoon half batter into buttered 8-inch square pan; spread evenly. Top with 1 1/2 cups strawberry jam. Cover with remaining batter. Bake in moderate oven (325 degrees) 1 hour or until slightly browned. Cool and cut into 1x2 inch bars.