Sift the icing sugar in to a bowl and add the golden caster sugar, almonds and vanilla sugar. Stir the ingredients together until all the ingredients are evenly distributed and the mix resembles fine breadcrumbs.
Beat the eggs in a cup. Make a well in the centre of the dry mix and add the egg and the Lemon juice. Using a spoon or knife make slicing actions from one side of the bowl to the other whilst turning the bowl with the other hand. Continue this until all the dry mix is moist with no dry mix present.
Dust a work surface lightly with icing sugar and empty marzipan mix onto it. Using your hands bring the mix together to form a dough. Wrap in cling film and place in the refrigerator for about 30 mins. Best to use within two days of making.