I am not real experienced but had a request for a filled cake. She would like a layer of blueberry filling and a layer of strawberry filling in a white cake. I did a trial run with just strawberry filling (used strawberry preserves) I had put an icing dam around the edge but when I cut the cake the filling ran out in the middle. Does anyone have any suggestions on this? I also thought it was too sweet, maybe I used too much filling or the wrong kind? Appreciate any advice!