1 c. butter
1/2 c. white sugar
1/2 c. brown sugar
1 tsp. vanilla
2 egg yolks
1 c. sifted flour
1 c. rolled oats
1 (12 oz.) pkg. chocolate chips

Cream butter, sugar and vanilla until well blended. Add egg yolks and cream until light and fluffy. Stir in the flour and oats. Blend well. Spread in greased 15 1/2 x 10 1/2 inch sheet. Bake at 325 degrees for 20 to 25 minutes. Cool slightly and spread with chocolate.

Melt chocolate chips in pan over hot water and add 1 teaspoon butter. Stir until smooth. Spread and cut into bars while warm.