This large can of beer was supported with straws, under each of the 3 layers, each on a cake board and a central dowel pushed through the whole thing. This is not the first time this has happened with tallish cakes. I know it is very hot and humid here but is that the only reason my cakes keep subsiding down. I make the cake and fill with very firm filling. Leave it to settle overnight. Cover with fondant and then watch and wait as it slowly sinks! Should I just keep to low structures!