Preheat oven to 325° F.
In a large bowl, combine flour, baking powder and sugar. Stir to blend and add egg yolks, amaretto, water and oil. Beat until smooth. Fold in beaten egg whites.
Pour into three 8-inch cake pans that have been greased and floured. Bake for 30 to 35 minutes. Cool in pans for 10 minutes. Remove from pans and cool completely on wire racks.
Whisk cornstarch into amaretto until dissolved. Place over medium heat, adding the marmalade. Heat until mixture is thick. Cool and spread between layers of cake.
Beat egg whites until stiff in a small bowl. Boil amaretto, water and sugar until mixture reached 242° F on a candy thermometer. With mixer running, drizzle the hot syrup into the egg whites.
Continue beating until mixture holds stiff peaks. Spread over top and sides of cake.Servings: 10