When I want to make mocha buttercream frosting, I just add
a tablespoon or so of instant coffee granuals to my regular chocolate buttercream frosting recipe. But that doesn't sound "blog worthy" though, sorry.
I like your blog idea. A few years ago I had the idea of giving someone in the family (that was hard to buy for) a dozen different cookies each month. I had so much fun planning what I'd make (lacey cookies for May, sandies for July, sunflowers for September), but the idea never became a reality!