Birds' Nest
["1 c. butter", "1/2 c. brown sugar", "2 egg yolks", "2 c. flour", "pinch of salt", "1 tsp. vanilla"]
["Form into small balls.", "Dip in slightly beaten egg whites. Roll in nuts; press hollow in center (using back of teaspoon). Bake 8 minutes in 350\u00b0 oven.", "Remove from oven and fill centers with jam or date-nut filling.", "Return to oven.", "Bake 10 minutes longer."]
["butter", "brown sugar", "egg yolks", "flour", "salt", "vanilla"]