Blueberry buttermilk coffee cake

I pulled out an old issue of 'Martha Stewart Living' the other day that had a delicious looking coffee cake on the cover. I remember making it another time, so I thought I'd give it another shot.
It's very tasty...dense but with a variety of textures and tastes.
The batter uses buttermilk and it's layered on the inside with blueberries (a good end of summer taste).
On top is a crunchy layer of honey/muesli with a streusel icing over that.
With a big cold glass of milk, my sister would say, "YUMMO".