Directions

1. Brush a 450g loaf tin with oil. As neatly as you can, line the bottom and sides of the tin with two strips of baking parchment. Melt 100g of the chocolate in the microwave with 1 tbsp vegetable oil on high in 30-sec bursts until smooth and glossy, then pour the melted chocolate into the loaf tin. Carefully spread the chocolate up the sides of the tin using a cutlery knife until they are all evenly coated. Put the tin in the freezer for 15 mins to set and take the ice cream out of the freezer to soften.
2. Take the tin out of the freezer and, working as quickly as you can, spread a quarter of the ice cream onto the base, then top with a single layer of chocolate mint thins. Add another layer of ice cream, followed by a layer of biscuits and mint thins. Top with another layer of ice cream, then a single layer of mint thins, before sealing with the last of the ice cream. Put back in the freezer to harden for at least 2 hrs or overnight. Don't worry if your layers are a bit messy - once everything has set and you cut a slice, it will look great.
3. Melt the remaining chocolate with the oil, leave it to cool a little, then, working quickly, spoon blobs over the ice cream and smooth over with the back of the spoon to cover the base. Return to the freezer until set. About 10 mins before you want to serve it, invert the ice cream bar onto a plate and peel off the baking parchment. Cut into six slices using a hot, sharp knife.