Melt the chocolate for the ice-cream in a large heatproof bowl over a pan of simmering water or in 30 second blasts in the microwave, stirring regularly. Leave aside to cool.

Grease a 20cm round, spring-form cake tin with oil, line the sides with parchment paper and set aside.

To make the base, melt the butter in a medium saucepan on the hob or in a bowl in the microwave. Blend the biscuits in a food processor, or seal them in a food bag and bash with a rolling pin, until you have fine crumbs. Mix the crumbs into the melted butter until well coated and spread evenly in the base of the tin with the back of a spoon. Pop into the freezer for at least 15 minutes to set.

Returning to the ice-cream, once the chocolate is cool, add the condensed milk and mix until thick and stiff. Using an electric whisk, beat the cream in a separate bowl, until stiff also. Fold the cream into the chocolate mixture until well blended.

Pour this mixture onto the set cake base, levelling the top with the back of a spoon. Arrange your chosen decorations on top. Freeze for at least 8 hours or overnight until frozen solid.

This will keep for up to three months in the freezer. Remove 10–20 minutes before serving (depending on how warm your room is) until soft enough to cut into. Drizzle the caramel over if using. Cut into 8 wedges. This is best done with a long sharp knife, which has been dipped in boiling water and wiped dry between each cut.

TIPS

Before serving, pipe on rosettes of cream if liked. A scattering of fresh or frozen raspberries and / or a drizzle of chocolate and / or caramel sauce before serving would be wonderful too.

Photo (c) Harry Weir