The secret to a really good chocolate coffee cake is the addition of sour cream which makes it rich and balances out the sweetness of the chocolate.
this was great. easy to make. i took the advise of another reviewer and added applesauce (about1/2 cup) since some said it was too dry. mine came out really moist. i also substituted brown sugar for the white sugar for the topping and mini chips. we will definitely make this over and over. has to cook a lot longer too. - 22 Aug 2004 (Review from Allrecipes USA and Canada)
I have made this cake twice now and they keep comin' back for more. And both times, I took the advice of other reviewers and added the half a cup of apple sauce, which makes the cake lovely and moist. I also divided the topping and swirled half of the mixture through the batter and the other half I put on top. This is definitely a keeper!! - 04 Sep 2006 (Review from Allrecipes USA and Canada)
This coffee cake was a big hit with kids and adults. I substituted dark brown sugar for the white sugar in the chocolate mixture and it was very good. I pressed down the topping before I baked (based on other reviewer's feedback) and that helped it adhere to the crust. For the second layer of batter, I dropped it in teaspoons and then spread it. The cake itself is not too sweet and the cinnamon/chocolate combo was great. Will definitely make again. - 19 Feb 2006 (Review from Allrecipes USA and Canada)