Oh, buttermilk raisin coffee cake, you soft and tender thing, you. This is probably my favorite coffee cake recipe (and that is saying a lot, because I have yet to meet a coffee cake I didn't like), probably because it is packed with juicy raisins and cinnamon and walnuts, and the buttermilk gives it just a teeny hint of tangy attitude. It also makes a nice generous amount because it cooks up in a 13x9 inch pan (and more on all that later), and is utterly and completely easy to make. You pretty much go from taking out the ingredients to pulling the golden deliciousness out of your oven in just under an hour, and then all there is left to do is wait for it to cool a little (So Hard!!) and then to slice it up and hand it out. You want coffee cake now, am I right? Let's make some!