In a large pan, start by melting the two types of chocolate along with the butter and golden syrup over a low heat. Stir every now and then until you have a smooth, slick, sauce.

Meanwhile, put the biscuits into a freezer bag and bash them with a rolling pin. Aim for a mix of differently sized biscuit chunks and crumbs.

Take the pan off the heat, add the crushed biscuits, mini marshmallows, and 300g of your favourite Christmas chocolates. Mix everything together and pour into a foil tray, spreading it as evenly as possible. Decorate with the remaining Christmas chocolates.

Pop into the fridge until the mixture sets (this will take around 2 hours, but overnight is fine too).

Once set, take out of the fridge, and allow to sit for 10 minutes before cutting into bars.

Arrange on a cake stand and sprinkle over the icing sugar or glitter.