The streusel coffee cake recipe in the BB cookbook is absolutely delicious, and has won many taste buds over to the whole-grain way of cooking.
You could try to cut back on the amount of butter (or oil, whichever you use) and substitute unsweetened applesauce. I do this in my muffin recipes.
You can cut the amount of oil in half and use that amount of applesauce instead. It maintains the moisture w/o the fat. I have not tried doing that with the coffeecake recipe. But go for it, and post your results!
P.S. I wouldn't try applesauce in the topping for the coffee cake. For that, just cut back on the amount of butter.
I did like you suggested. For a doubled streusel coffee cake recipe, I used 1/2 c oil and 1/2 c applesauce.
Yummmm! It turned out really well.....my kids are going to love it!
Thanks so much!!