Any time you have a filling that’s soft or runny (i.e. lemon curd, peach compote, chocolate ganache, etc.), you’ll want to pipe a rim of frosting around the edge of the cake layer before adding the filling. I typically pipe the rim of frosting about a quarter inch in from the very edge of the cake. Also make sure you don’t put too much of the filling in. Using too much filling will cause your cake to be unstable while you stack and decorate. Save the extra filling and serve it on the side of your cake slices instead.