Scotch Bars
["1/2 c. butter", "1/4 c. granulated sugar", "1/4 c. brown sugar, firmly packed", "1/2 tsp. vanilla", "1 egg yolk", "1/2 c. sifted flour", "1/2 c. rolled oats", "1 (6 oz.) pkg. chocolate chips", "1/2 c. chopped walnuts"]
["Cream butter, both sugars and vanilla thoroughly.", "Add egg yolk and beat until light and fluffy.", "Stir in flour and oats; blend well.", "Spread in greased 7 x 11-inch pan.", "Bake in moderate oven (350\u00b0) for 20 to 25 minutes.", "Remove from oven and allow to cool. Melt chocolate chips over hot water and stir until smooth.", "Spread over baked cookie and sprinkle with nuts.", "Cut into bars while still warm.", "Chocolate will become firm.", "Makes 2 dozen."]
["butter", "granulated sugar", "brown sugar", "vanilla", "egg yolk", "flour", "rolled oats", "chocolate chips", "walnuts"]