To make the biscuit dough, place 100 g of demerara sugar, 250 g of sieved flour, a tablespoon of ground ginger, a pinch of salt and a teaspoon sodium bicarbonate in a bowl and combine the ingredients using a whisk.
Beat the egg in a bowl and add the diced candied ginger.
Pour the Cadí butter into the egg mixture and combine well.
Make a well in the middle of the flour and sugar mixture and pour in the egg. Combine with a fork and then mix with an electric whisk. Bring the dough together in a ball and leave to rest for 30 minutes.
Roll out the dough and cut into biscuits.
Place the biscuits on a baking tray lined with baking parchment and bake in the oven at 180 ºC for 15-20 minutes.
Remove from the baking tray and parchment and leave to cool on a cooling rack till they go crunchy. They are now ready to eat.