I have always adored jam filled anything! Jellyroll, Trifle, Thumbprint Cookies,..you name it! These are the easiest cookies in the world to make and they are by far some of the best you will ever have. If you have priced cookies made with real butter in the store recently, you will know that it makes good economical sense to make them yourself. You may have to keep your eye out for commercially made Lemon Marmalade or Jam. I believe I purchased my jar imported from Italy at World Market. Do not mistake Lemon Curd for Jam. Lemon Curd is perishable at room temp and should not be used here.