Preheat the oven to 350 degrees F. Grease and flour three 6-inch cake pans (they should be at least 3-inches high). Set aside.
In a medium bowl, mix together the flour, baking soda, baking powder, salt, cinnamon, cardamom, and allspice. Set aside.
Beat the butter and sugar together until light and fluffy. Beat in the eggs one at a time. Mix well between each addition of egg.
Alternate between adding the flour mixture and apple sauce. You should add the flour in three additions, and the applesauce in two additions. Begin and end with the flour mixture.
Fold in the chopped apple.
Evenly distribute the batter among the three cake pans. Spread the batter in the cake pans so the tops are an even layer.
Bake for about 30-35 minutes, or until a toothpick comes out clean and the sides of the cake pull away slightly from the pan.
Run a knife between the sides of the cake and the pan. Allow to cool for about 30 minutes before removing from the pan and allowing to cool completely on a wire rack.
Cover tightly and chill in the freezer as you make the frosting.
Beat the egg whites, powdered sugar, and salt for about 10 minutes (this is best done with a stand mixer with a paddle attachment or a hand mixer).
Add the butter one cube at a time, mixing until the butter is completely incorporated before adding more. Beat in the vanilla and cinnamon. The mixture may look broken, but keep beating for at least another 10 - 15 minutes, or until the mixture becomes smooth and silky.
Remove the cake from the freezer and level the cake as needed.
Add some of the frosting on each of the layers, then place each layer on top of one another. Add some of the frosting to the sides of the cake and smooth, removing any excess frosting as needed.
Drizzle the caramel over the top of the cake. Dip the apple in the caramel, then place on top of the cake.