I did a 9x13 inch cake for my family (Black Forest) Chocolate Cake with Cherry filling. I created a damn and then I spread some chocolate icing on the cake and then I put the cherry filling on top of the chocolate icing and then I put the top layer on the cake. I let the cakes set overnight and then after I put in the cherry filling I let the cake settle for about 1 hour before I iced it. I guess I should have pushed tiny cake scraps in between some of the small cake gaps. The gaps were very small and I did not think it would show or cause a bulge. After doing all of this I still had a center Bulge. I thought I was following all of the steps I had read about doing a cake with fruit filling and trying not to get a center bulge. I was a little afraid that after I iced the cake the cherries made the cake a little bit unsettling meaning I was afraid the top layer was going to fly off if it was moved tooo much. I bake all of my cakes at 325 degrees for this very reason so they will not puff up too much.
For my next attempt with fruit filling what can I do to prevent the center bulge and to make the cake a little more stable so I will not fear the top layer coming off.

I'm guessing you used a filling with actual cherries in it, like a pie filling, which would cause a thicker layer? In that case, you could always make another wall on top, just to make sure your dam is high enough. Was your buttercream stiff enough? It sounds like you tried hard not to get the bulge, sometimes they happen!
As for the top layer slipping, that was likely caused by the chocolate icing layer underneath. You could always mix your fruit filling into buttercream - that will make a more stable filling.
Perhaps someone more experienced has more ideas for you on the bulging...

Did you make your dam right on the edge or did you make it inward about a 1/2 inch? I put mine in a little to leave room for the settling. Beachcakes had lots of great advice.

tastycakes is right! I forgot to mention that! I don't put the dam right on the edge either... when you ice the sides, it will fill in.

A dowl or skewer down throught the middle should stop your slipping problem. When you make you dam, make sure it is tall enough and make it with extra thick BC... not the kind you frost the cake with. I mix powdered sugar with my BC to make a really stiff frosting. This works great.

Thanks, all very good advise. I like the idea of not having my damn so close to the edge and making it tall enough and extra still enough to hold in the fruit filling. In fact, like I said, I liked all of the ideas. I will definitely try mixing the fruit with the buttercream. But in this case this family member loves cherries and I thought about doing that but I thought I would have too much of the chocolate flavor and not enough of the cherry flavor.

Thanks