I had left over mashed potatoes from the Bangers and Mash experiment earlier this week (post coming).
As I have discussed before- one of the best things to do with leftover mashed potatoes is to make mashed potato soup!
I won't go into the procedure again, but I'll link you to the original post.
This afternoon, I'm on to homemade Rugelach! I can't wait to see how it all turns out. I'll be sure to post the results.