I got the coffee-cake recipe from this website http://allrecipes.com/Recipe/Coffee-Cake-Literally/Detail.aspx . Just follow that recipe each ingredients and each steps. It was great and perfect. I would say that if you like strong-coffee, just add 1-2 more spoons than is stated in the recipe. And make sure that the coffee-butter mixture is cold enough when you want to mix them with the flour. The cake turns out to be soft, not so spongy (which is good), moist, and perfect-sweet.
I put the frosting over the cake when it’s cold. Usually I use cream cheese, but I didn’t have it that time and I have sour cream. So I searched the recipe for cake frosting from sour cream. I found this http://allrecipes.com/Recipe/Sour-Cream-Chocolate-Frosting/Detail.aspx . Instead of using confectioners sugar, I used a normal sugar. This frosting recipe was way too-sweet for the coffee cake. I used 6 tbs of sugar instead of 2 3/4 cup as stated in the recipe. But it’s still too sweet. I think my chocolate chip is sweet enough (I used 1/2 cup of this one http://www.appiehein.com/2215-1949-thickbox/sprinkles-pure-de-ruijter-5-boxes.jpg).
But overall the cake was so good (it would be perfect if it was less sweet)