This is the simplest of all the buttercream recipes. With just a couple of ingredients and a good beating, everyone is a winner. Well-made buttercream has always been my favourite part – the rich, sweet naughty creaminess is hard to beat. When I had my bakery we would always use the same quantities for the vanilla buttercream: half butter to sugar, plus flavourings. This makes enough buttercream to cover a three-layer 20cm cake.