By request here is the cake recipe....
For the cake, use one box dark chocolate cake mix (or, if you prefer, a from-scratch equivalent) and bake in 3 round cake pans. (I baked them for only about 20 minutes.)
Let cool completely then level off the cakes.
8 oz cream cheese, softened. 1 packed cup brown sugar. Cream these together until smooth, then add 1 and 1 half cups thawed Cool Whip. Use this between each layer of the cake and smooth, smooth, smooth the edges. (This is what I did: I didn't know if this filling was just supposed to be used between the layers ONLY or to also FROST the outside of the cake so I put in extra whipped topping and frosted as well as filled the cake, because I am NOT good enough to make the filling really smooth on the edges.)
Then you put the cake in the freezer for about 30 minutes.
Melt 4 oz squares unsweetened baking chocolate (I used semisweet once, I don't think it matters too much) and mix well with 3 cups powdered sugar. Add boiling water a spoonful at a time to make a smooth glaze. Pour over cake.
Use extreme self-control and don't eat any until you can show it off! Ha.