Buttermilk... I have so much buttermilk left over... Does anyone know of any delicious yet simple recipes (baking or cooking) that use this ingredient?

(slightly) Longer version: I recently made lemon poppyseed muffins (which turned out fantastic!), and they required buttermilk. The smallest size I could buy was a 2L jug, of which I only needed two cups! So now I have almost a full carton of buttermilk in my fridge, and haven't got a clue as to how to use it. I'm looking for anything, baking or cooking, which would be relatively simple (I'm a poor college student) and obviously delicious. Thank you!

bon appetit