The coffee cake was a hit with our community group! I read a few of the reviews and was concerned it wouldn't be moist enough. I added approximately 6 tbsp. extra sour cream and 2 tbsp. extra butter to the cake recipe. I also made slightly more streusel mixture. I also doubled the powdered sugar mixture, so I could squeeze it out of a ziploc bag. It was very moist and not overly sweet. Perfection!