Sieve the icing sugar into a large bowl, then stir in the caster sugar and ground almonds.

Crack the egg into the centre of the mix, and sprinkle over the brandy and almond essence.

Using a palette knife, stir to combine, then turn out onto a board dusted with icing sugar.

Knead into a smooth paste, taking care not to over-knead - excess handling can make the ground almonds seep oil and turn the marzipan greasy.

Use immediately, or pop it in the freezer ahead of time if you are prepping for an organised Christmas!