Grease & flour an 8x1 1/2" layer pan. Make cake as package directs, using egg & amount of water specified on package Bake at 350~F for 30-35 minutes. Cool in pan 10 minutes. Cool on wire rack. Make filling: Whip cream & sugar unitl stiff. Gently fold in extract. Split cake in 3 layers. Spread each layer with 1/3 cup jam and then 2/3 cup whipped cream mixture. Refrigerate several hours before serving.