This cake is relatively straightforward to make, but it looks very impressive. The cake layers can be made in advance and frozen (once layered between pieces of parchment paper). Don’t let the piped effect put you off making this cake. If preferred, the buttercream can simply be spread on for a more simple finish.
TIP - Use blueberries, strawberries or mixed berries instead of raspberries if preferred. Just ensure the purée is cooked enough so that it’s almost jam-like rather than watery before adding to the butter.