Argh... I was trying to make a birthday cake for this evening and instead it appears that I've made a hot mess. I made this vanilla cake from The Cake Blog, which I've made before and like. I also made it's accompanying Swiss Meringue Buttercream. I wanted to decorate it like this cake from Sweetapolita and I liked her filling idea.

I made my cake and buttercream last night as well as the blackberry compote from Sweetapolita. I just went home over my lunch break with the (admittedly ambitious) goal of making Sweetapolita's whipped mascarpone filling and at least crumb coating the thing. I probably should have changed course when I looked at my blackberry compote and noticed it was more runny than compote-y, but I figured I'd followed the directions and decided to plow on. Worried that I might not have quite enough compote I did dig out a jar of lemon curd to supplement. 

So I put down my first cake layer, and piped a dam with some of the buttercream. I then laid down some of the whipped mascarpone filling, and then a layer of lemon curd, filling it up to close to the top of the dam. I next proceeded to put down the second layer of cake and repeat the process, but instead of topping with the curd, I used the compote. I then added the third and final layer of cake at that's where my troubles began.

The compote started to run almost immediately. I ended up spinning my turntable around frantically and just wiping it from the sides of the cake and off the cake board. Once it seemed like it was mostly wiped off, I started to attempt the crumb coat with the Swiss Meringue Buttercream, but it was further downhill from there. It may have been the additional weight of the buttercream on the cake, but before I knew it, the cake was oozing compote and curd, my dams looked like they were broken, and my layers were sliding all over the place. Worried that I wouldn't have enough Buttercream and having a hard time getting it to stick to the increasingly wet sides of my cake, I grabbed the extra mascarpone filling (of which I had plenty) and which had gelatin in it, so I was hoping might help hold the thing together. I managed to sort of get a thickish layer of (now partially purple and yellow) frosting to cover most of the outside and slammed the thing into the fridge. I'm going to check on it to see if it's hardened up and is salvageable after work, but I'm not optimistic.

So... what did I do wrong? I have a few thoughts, but would love to hear any additional ideas or suggestions. 

1. Should I not be crumb coating with a Swiss Meringue Buttercream? I've always preferred Meringue Buttercreams to frostings based on just butter or shortening (blah), but they never seem to work that well as a crumb coat. Personally, I find the Swiss version to be a little more rubbery in texture (vs. something like an Italian), which I don't love, but I like the idea of directly heating the eggs first as I think it makes it safer.     

2. Should I have chilled the dams before filling them or chilled the entire cake as I added each layer?

3. Am I filling the dams too high? I filled them almost - but not quite - to the top, but they were nice thick dams. I thought they'd hold.

4. I've never had a ton of luck getting fruit to thicken up without using an added thickener. I followed Sweetapolita's directions which didn't call for a thickener, but ended up with something more syrup-y than compote-y. Is there a secret I don't know?

Anyway, I'd love to hear any ideas on how I can avoid this situation in the future.

........Should I not be crumb coating with a Swiss Meringue Buttercream?.....

Nahh - your problem is w/the filling.  You mention it looked sort of soupy.  That's where you should have stopped.            

...........Should I have chilled the dams before filling them or chilled the entire cake as I added each layer?........

No real need.   I doubt it would have helped....          ............... Am I filling the dams too high?............No - that's about right.

Can't help you on ? #4 as I've never used that recipe.

If you never have luck getting fruit to thicken without using a tickener, why not use one?  It is likely that the fruit just needs to cook down more in volume.  I know Lynne doesn't, but I always frost my cakes chilled, but I agree that it would not have made any difference, in this case.

I've had no problems crumbcoating with SMBC.