Mix the caster sugar with the lemon juice; add the rind, sherry or wine, and brandy.
Warm slightly in a bowl over hot water (a bain marie) to dissolve the sugar and blend the flavours. Do not overheat the mixture.
Whip the cream into soft peaks and fold into the liquid.
Pour into tall glasses and let the mixture rest and separate.
To make the biscuits, preheat the oven to 190C/375F/Gas 5. Combine the flour, baking soda and spices in a bowl and set aside.
Now cream the sugar and butter. Once combined, beat in the egg and golden syrup until light and fluffy.
Stir in the flour mixture and combine. Using a teaspoon, spoon small amounts of the mixture onto a lightly greased baking sheet around 5cm/2in apart. Slightly flatten down and sprinkle with sugar.
Bake in the oven for 8-10 minutes. Serve with the syllabub.