Cream butter and sugar, add egg yolk and beat thoroughly. Sprinkle flour over graham crackers, add baking powder and salt. Add milk alternately. Fold in egg whites, mix lightly and add nuts. Bake in 2 greased and floured pans 30 minutes at 350~. Frost with apricot whip. Put apricots in blender to make puree, cook in juice from apricots until thickens to jam. Chill. Fold whipped cream into jam. Add vanilla. Spread over cake. Keep refrigerated until ready to use.
