My great grandmother's coffee cake

I should start this with a disclaimer: This recipe is a family secret, and I have been sworn to secrecy.  BUT....I baked it tonight for breakfast/brunch tomorrow morning, it's in the oven right now, and my apartment smells awesome.

This cake makes an appearance at almost every family holiday meal (with the exception of Passover, and that is simply because it's not kosher for Passover) - baked by my grandmother.  Originally, years ago, my aunt copied over my great grandmother's handwritten and annotated recipes (what I would pay to see her originals!) and gave them to my mom, my grandmother, and my other aunt in a binder.  When I make this cake, I always think about my great grandmother Rose, whom I called Nanny Rosie, whom I was lucky enough to know (and remember). 

Me as an infant with my maternal grandmother, maternal great grandmothers
(Rose and Sadie), and mom
(please excuse the flash)

Inside the cake are layers of cinnamon-sugar and golden raisins (I usually use regular raisins but opted today for golden ones instead).