The Lemonade Layer Cake!
If you don't feel like baking right away, you can freeze buttermilk. Try doing a search - I bet there are a million and one ideas out there.
"In all our woods there is not a tree so hard to kill as the buckeye. The deepest girdling does not deaden it, and even after it is cut down and worked up into the side of a cabin it will send out young branches, denoting to all the world that Buckeyes are not easily conquered, and could with difficulty be destroyed." - Daniel Drake, 1833