Preheat the oven to 165C (330F). Line at least one baking sheet with parchment.
Cream the margarine and sugar till fluffy. Add the egg, bicarb and spice and mix well.
Add about a third of the flour, and a third of the dates, and mix well. Add another third of each, and mix. Add the final third of the flour and dates, and combine everything thoroughly to give a stiff dough.
Allow the dough to stand for 5-10 minutes to firm up slightly.
Take walnut-sized blobs of the dough, roll into balls, and flatten into discs. Place on a baking sheet and bake at 165C (330F) for around 10 minutes until golden. They will spread slightly in the oven, so leave some space between them.
Allow to cool for a minute or two on the baking sheet before transferring to a wire rack to cool completely.