I saw this in the Fall issue of Kraft Food and Family, (click "sign up" in the top right corner to get the magazine) and thought it looked awfully pretty and fairly simple. I've made it three times now, and it's always a huge hit. Click the picture for the recipe. (or the words)
Boston Cream Pie Recipe
Since it only uses one layer, you can freeze the other and have it ready to make another one super-de-duper quick.
For the chocolate on top, I've done some fiddling. Today I cut the milk to one T, heated it before I added it to the chocolate, and used a bit more sugar. That made a nice consistency. I thought it was too runny when I followed the recipe.
I like this especially because I get to use my domed cake plate, and cut the cake in half, so I feel like a real cook. Enjoy!