According To One Bakery Pro, You Might Want To Start Squishing Your Cake
Keeping the cake layers properly in place while frosting takes a little finesse because the last thing you want is for the layers to slip around. The Takeout spoke to Victoria Fisk, cofounder and confectionery chef at Bouqedibles, about some ways to handle your layer cakes so that they stay bound together. And one of the things Fisk suggested is a bit of gentle manual coaxing to ensure everything stays in place.
Fisk said, "In most cakes, gentle pressure helps bind the frosting and the sponge together. When you are working with a complex filling, you need a buttercream barrier to keep the filling from oozing out, and pressing the layers gently helps make sure that barrier is secure."
Don't forget to keep your cake aligned properly, too. Fisk said that since the positioning of the layers is all dependent on each layer's relationship to the bottom sponge, arranging your layers evenly is important. If everything's aligned properly, that'll help ensure that the cakes, filling, and frosting don't slide.
But before you start frosting, make sure of one thing
There's one key thing you'll need to make sure of before you start frosting: Your cake rounds or rectangles should have completely cooled down. I have impatiently made this mistake before, and almost any residual heat will result in slippery layers, thanks to the heat softening (or even melting) your frosting. Buttercream is a particularly delicate type of frosting in that the butter in it can melt easily, so plan ahead and be patient. Rushing might ruin the entire cake.
Evenly cut cake layers also help everything stay in place. You can use toothpicks and a serrated knife to guide you as you cut and remove any dome-shaped parts from the cake. Not only will it help the layers not shift, but it'll create a uniform product that's sure to look good once you slice into it. Combine that with a bit of pressure (not too much) as you frost away on your cake stand, and hopefully your cake will look exactly how you dreamed it would.