- 275g/9¾oz plain flour
- 40g/1½oz cocoa powder
- ¾ tsp bicarbonate of soda
- ½ tsp flaked sea salt
- 200g/7oz unsalted butter, softened and diced
- 50g/1¾oz caster sugar
- 200g/7oz light brown sugar
- ½ tsp vanilla extract
- 85g/3oz dark chocolate (60–70% cocoa solids), finely chopped
- 40g/1½oz mint-flavoured candy cane, roughly crushed
- 250g/9oz dark chocolate (60–70% cocoa solids)
- 3-4 mint-flavoured candy canes, crushed to a coarse powder, to sprinkle (optional)
- For the dough, sift the flour, cocoa and bicarbonate of soda into a medium bowl. Grind in the salt and stir. Set aside.
- Put the butter in large mixing bowl and, using an electric mixer, beat until smooth and light. Add the sugars and vanilla extract, and beat for 2 minutes, or until smooth. Add the dry ingredients to the bowl and mix until the dough looks sandy (which is what sablé means in English).
- Add the chocolate and candy cane to the bowl, then mix. The dough should look almost like soil; it should not have formed into one large ball. If mixed for too long the biscuits will be tough.
- Tip out the dough onto a work surface and gently press together. Divide in half and roll into two logs, about 4cm/1½in thick. Wrap each log in cling film and chill for 3 hours, or until firm. (Alternatively, wrap the second log in brown paper and tie the ends up. Freeze the dough for baking at a later date.)
- Preheat the oven to 180C/160C Fan/Gas 4. Line three baking trays with baking paper.
- Using a thin, sharp knife, cut the logs into rounds about 1cm/½in thick. Put the biscuits onto the baking trays, leaving 2cm/¾in between each one. Bake for 10–12 minutes, or until set on the outside but soft in the centre.
- Leave the biscuits to cool on the trays for 10 minutes, then transfer to a wire rack to cool completely.
- To decorate, line a baking tray with baking paper. Temper or melt the chocolate. Dip each biscuit halfway into the chocolate, allowing the excess to drip off. Put onto the prepared baking trays and sprinkle with a little crushed candy cane. Leave to set. The biscuits will keep for up to a week stored in an airtight container.