Grease the forms extra well with softened butter, and dust the forms well with finely ground bread crumbs. Mix almond paste and powdered sugar. Add egg whites Mix well. Place bowl in hot water and knead dough until it is lukewarm. Turn out on board sprinkled with 1/4 cup powdered sugar. Let rest 10 minutes. Knead 2 to 3 minutes. Press dough through cookie press into greased ring forms. The hole in the cookie press disk should be approximately 1/2" in diameter, or dough can be rolled out by hand. Bake at 300° F. for 20 minutes. Do not remove rings from forms until cold.
Use decorating nozzle to apply frosting on each ring, and place each ring on top of one another. The frosting will keep the ringsfastened together. Keep the cake in a sealed box. Place a fresh piece of bread or a peeled potato in the box for two days before you serve it to make the cake chewy. The cake can be frozen, and normally becomes chewy when defrosted.
18 Rings