Step 2

Beat the butter and sugar until fluffy and pale, about 5 minutes. Add eggs one at a time, beating for 1 minute after each. Beat in the vanilla, then gently fold in the flour mixture.

Step 3

Spoon into the tin and bake for 35–40 minutes until a skewer comes out clean. Cool completely on a rack in the tin.

Step 4

Make the frosting: sift the icing sugar into a bowl and add the mascarpone, cream and pistachio paste. Beat until combined. Refrigerate for 20–30 minutes to thicken.

Step 5

Cut the cooled cake in half horizontally with a serrated knife. Place the bottom layer on a plate and spread generously with pistachio cream. Top with a generous handful of raspberries.

Step 6

Place the top sponge on and cover the top and sides with the remaining cream. Scatter the remaining raspberries, reserved whole pistachios and lime zest on top.