Cinnamon Streusel Coffee Cake

I recently craved cinnamon streusel coffee cake. I don't drink coffee, of course, but we had received a postcard in the mail from a local realtor that had a recipe for it. I tossed the card into the recycling and was very shortly sorry. So I googled around for an easy-enough recipe that would produce the fluffy breakfast baked good. I decided on the King Arthur Flour recipe, and I even purchased a 5-pound bag of their product, since I was going to need ~5 cups of the stuff!

I prepared the batter on Friday night so that we would only have to wait a little over 1 hour Saturday morning for the oven to warm up and the coffee cake to bake. The preparations took about an hour and used up almost every measuring spoon and cup plus multiple bowls (wet ingredients, dry ingredients, filling, topping). I have never made a marble cake, so the instruction to swirl the batter and filling with a knife was hard to follow. Streusel topping was also new to me, and I think I broke it up too finely. 

Final critique: I'm not sure I successfully balanced getting the center "done" while not over-baking the outer portions. A 9"x13" pan makes a LOT of coffee cake! We will probably eat half over the next week, and then I'll freeze the other half for a month or so. What a treat to get it back out of the freezer to eat on some more. Despite almost 4 cups of white and brown sugar, Dear Husband declared it delicious and not too sweet. I'm so lucky he lets me "experiment" in the kitchen like this and know what I'll make the next time I host/attend a brunch.