Last night I was looking for a recipe that wouldn't require a lot of time, and I stumbled across a recipe for "Coca-Cola Cake" from Lisa Yockelson's ChocolateChocolate. You can make this cake -- from start to frosted finish -- in less than an hour, which is pretty remarkable. Fortunately, we also happened to have a few cans of Coke left over from our holiday party, and a half-full carton of buttermilk in the fridge (left over from my farm stand buttermilk doughnuts), so I even had all of the recipe ingredients on hand.
To make this cake, you whisk some buttermilk and baking soda together and set it aside. Then you bring a mixture of Coca-Cola, cocoa powder, and butter to a boil on the stove. Meanwhile, you put flour, sugar, and salt into a bowl, pour over the hot Coca-Cola mixture, and mix until combined, followed by eggs, vanilla, and the buttermilk-baking soda mixture. The resulting batter is extremely thin, probably the thinnest cake batter I have ever worked with (to the point where I was seriously questioning whether it could possibly really turn into a cake). You pour the batter into a 9-inch by 13-inch pan, and bake the cake at 400 degrees for 20 minutes.
While the cake is hot (only 5 minutes out of the oven), you frost it with a mixture of melted butter and chocolate, powdered sugar, vanilla, and Coca-Cola. The frosting melts and slides around when you put it on the hot cake, but firms up into a smooth, shiny glaze as it cools.
This cake looks like an ordinary chocolate cake, but it definitely doesn't taste like one. The cake doesn't contain that much chocolate (1/4 cup of cocoa powder in the cake and 2 ounces of chocolate in the frosting), and it's difficult for me to describe the precise flavor. Not exactly like drinking a Coke, but this cake definitely has a sweet, caramel-y extra something. It was also extremely moist. I liked the consistency of the thin layer of frosting, and the frosting flavor was very complementary to the cake; both were very sweet. I thought this cake was tasty, but nothing spectacular. However, I received quite a few rave reviews on this cake from others, so I would definitely be happy to make it again.
Recipe: "Coca-Cola Cake" from ChocolateChocolate by Lisa Yockelson, recipe available here (scroll down a few questions, to the recipe request from "Cake lover").