Tiramisu Cake Chocolate Dessert

This is a different way to serve a great tiramisu.
A choclate cake version, good for chocolate lover's.
It's easy to make and everybody likes this one.

Ingredients:
1 package (18.5 ounces) devil’s food cake mix
1 package (8 ounces) cream cheese, softened
1/2 cup powdered sugar
1/2 cup sour cream
1/2 teaspoon rum extract
1 container (8 ounces) frozen whipped topping, thawed
1/2 cup sugar
1/4 cup instant coffee granules
1/3 cup boiling water
1 bar (8 ounces) semi-sweet baking chocolate (such as Baker’s)

Directions:
Prepare cake mix according to package directions; cool.
In a large bowl, whisk together the cream cheese and powdered sugar
until smooth. Whisk in sour cream and rum extract.
Fold in whipped topping with electric mixer.
In a medium bowl, stir together sugar, coffee granules,
and boiling water until dissolved; brush mixture over cooled cake.
Spread cream cheese mixture over cake.
Grate chocolate bar over cream cheese mixture and refrigerate.