Non-Coffee Tiramisu

I have heard people rave about tiramisu for years, yet I have never got to try it.  I looked up recipes and I found quite a few.  The problem for me was with the ingredients.  You see, I don't drink coffee or alcohol, and tiramisu's success is based on that.  So I scrammed my brains and substituted hot chocolate for coffee and rum essence for the alcohol.  It worked like a charm!  It was INCREDIBLY DELICIOUS!  Mmmm!   Also, from the recipes I gathered, it seems that it can be done with either lady fingers or sponge cake.  I went for the sponge cake.  It came out like the prajituri (little cakes) I remember from growing up in Romania.  Soooooo good!  Enjoy!
For sponge cake:
-1/4 cup margarine
-1/4 cup milk
-2 eggs
-3/4 cup sugar
-3/4 cup flour
-1 tsp baking powder
-1/4 tsp salt
-1/4 tsp vanilla extract
-3/4 cup hot chocolate (ready as if you were to drink it)
For topping:
-1 (8 oz) package cream cheese, at room temperature
-1 (8 oz) package mascarpone cheese***(see note for substitute)
-1/3 cup powdered sugar
-1 1/4 Tbs rum extract
-2 cups heavy cream
-grated milk chocolate (as much as you want :)
Preheat oven to 375 F.  Spray 9x13 inch baking pan with cooking spray.
In a small sauce pan, combine milk and margarine.  Heat until margarine is completely melted.
In a large bowl, beat the eggs at high speed until light.  Add sugar and beat for 2 more minutes.  Add flour, baking powder, salt, vanilla and hot milk mixture.  Beat at low speed until smooth.  Poor into prepared pan.
Bake in preheated oven for 14-16 minutes, or until cake springs back when touched lightly in center.
Pour hot chocolate over warm cake.  Let it cool for at least 30 minutes.
While cake cools, combine cream cheese and mascarpone cheese.  Beat until smooth and creamy.  Mix in powdered sugar and rum extract.
In a different large bowl, beat heavy cream until stiff peaks form.  Fold this into the cream cheese mixture until well combined.  Spread evenly on cooled cake.  Sprinkle grated chocolate all over.  Cover and refrigerate for at least 4 hours (recommended to refrigerate over night).  Enjoy!
*** NOTE:
If you can't find mascarpone cheese, simply use this great and simple substitute: mix together 1 (8 oz) package of softened cream cheese with 1/4 cup heavy cream and 2 1/2 Tbs sour cream (it has to be regular not low fat).