Gently heat the orange juice with the sugar in a pan until the sugar dissolves (but do not boil, as the gelatine will be less effective). Soak the gelatine leaves in a bowl of cold water for about five minutes, or until they are soft and pliable. Remove them from the soaking water and squeeze out any excess water with your hands. Stir them into the warm orange juice.

Pour the orange juice through a sieve into a glass trifle bowl. Place in the fridge to set. This can take up to four hours, depending on your fridge.

Next, make a syrup by dissolving the sugar in the water in a saucepan over a gentle heat until the sugar has dissolved. Allow to simmer for a few minutes then take it off the heat and stir in the whiskey.

Whisk 300ml of the cream until it holds its shape, then fold in the mascarpone cheese, icing sugar and vanilla. Fill a large piping bag with the mascarpone cream.

To assemble: Peel the mandarin oranges, cut them in half and then into slices. Arrange the slices around the perimeter of the bowl on the jelly and over the jelly. Pipe half of the mascarpone cream in the centre of the bowl on the jelly and around the orange slices. Dip the sponge biscuits in the whiskey syrup and layer on top of the mascarpone. Finish with another layer of mascarpone. Cover and leave in the fridge for a couple of hours or overnight. Before serving, whip the remaining 200ml of cream and spread it over the trifle.