You've added too much water instead of a splash. The filling should be thick and spreadable. Never runny. If your mix is a bit too runny, you can try simmering for a little while to let some of the liquid absorb, but it's important to not add too much liquid to begin with. If it seems a bit runny after cooking (but wasn't to begin with), allow it a chance to cool. It'll stick together better if you let it cool before serving.