Start this recipe by lining a 7 or 8inch cake ring with baking paper on the base and sides. To make the berry compote, place 250g of frozen berries into a pan with the sugar and cook for 5 minutes until the sugar is dissolved. Allow to cool down completely and mix in the lemon zest. Remove some of the liquids to use as soaking syrup and mix in the liqueur. Cut the round sponge into 3 slices and place 1 slice in the bottom of the cake ring. Drizzle with 1/3 of the soaking mixture and cover with a layer of vanilla ice-cream. Spoon over 1/3 of the berry compote and cover with another layer of sponge. Soak the sponge again with ½ of the liquids, cover with a layer of strawberry ice-cream, then with ½ of the compote. Place the 3^rd sponge on top, soak again and cover with another layer of vanilla ice-cream. Flatten out well and place in the freezer for at least 4 hours. To serve, remove the semifreddo from the ring and remove the paper. Place onto a cake stand and decorate the sides and top with the macaroons, fresh berries and mint leaves.