For best flavor and texture, ground poppy seeds are a must. You will find the mixture in finer spice stores and European markets or order it from places like www.TheSpiceHouse.com online. Or, get a poppy seed grinder and grind the poppy seeds yourself. Just soaking poppy seeds does not soften them enough nor does a food processor or coffee mill do an adequate job. IF you cannot find a grinder nor ground poppy seeds, then 'doctor' up store-bought poppy seed filling with ground raisins, grated apple, some jam, a bit of honey and it will still be quite exceptional.