Where I live is always hot weather.
I am having trouble especially with cakes that have fillings, the buttercream forms like a bump on the sides of the cake.

Did this happen to anyone?

Do you allow your cakes to settle (for a few hours or even overnight) after filling before you frost them? This could be one cause.

Oh NO!!!!!

I fill and then decorate one time.

Hi, I'm in the Bahamas so I know what you mean about the heat . I cool my cakes completely and then wrap and refrigerate. If I don't make them enough time to refrigerate, then I allow them to cool for awhile on a rack. You can even just wrap and leave overnight, without refrigerating. Letting them rest and set really makes a difference when you start filling and frosting. Make sure you use a crisco-based buttercream (I use Indydebi's) and make a really good dam around the edge of the cake before you add the filling. That will help hold it in and keep your edges from bulging. The dam isn't necessary if your using only buttercream for filling.

Hope this helps .

also... do you make a buttercream dam around the inside of the layer.... not right at the edge.... but just a little ways in... make sure the dam is thick enough..... put your filling.... not real heavy.... then let it set up a little while.... then ice your cake with an icing that is not too thin.... but not too thick either... hth

topaz176: I looked at your website...your cakes are awesome ! You're obviously doing a lot of things right , even if your buttercream is misbehaving !

I had a birthday cake last month that was going to a park in 98 degree Florida heat and 90% humidity! Used Indydebi's recipe with Hi Ratio shortening and it held up beautifully! I also take out some of the frosting from the mixer bowl when it's really stiff to save for the dam before I add enough liquid to get the softer spredable consistancy I use for the outside.