In this video I am going to show you how to frost a cake without crumbs. If this step is omitted crumbs will show up in the final layer of frosting which affects the overall look of the cake.
The process of keeping crumbs away from the outside of the cake is called crumb coating. When cakes are baked and cooled, they need to be filled with frosting of . your choice which can be buttercream and/or another filling like jam, curds, ganache et cetera.
When the cake is filled it is time to crumb coat. A crumb coat is a thin layer of buttercream/ganache that is used to seal in crumbs so that they do not attach to the final coat of icing.
Make the butter cream and spread some on the cake and cover the whole cake with a thin layer of icing. You can use a spatula to smooth it out. Put this in the fridge to firm up.
When firm you can now put the final layer/layers of frosting until it is as smooth as you want it to be.
If you want to put fondant on top of the cake you chill the cake again and then you put fondant on top.