1-Start by beating 175g softened unsalted butter and 150g golden caster sugar until light and fluffy. Add 1 medium egg, 1 tbsp instant coffee, and ½ tsp vanilla bean extract, then mix well. For the next part, combine 200g plain flour, 50g cocoa powder, ¼ tsp bicarbonate of soda, and a pinch of salt; add this to the mixture and mix briefly until a dough forms.

2-Chill the dough for 1 hour to make it easier to handle. Roll the dough into balls using about 2 teaspoons of dough each, then coat them in 60g toasted chopped hazelnuts. Place the coated balls on baking trays, spacing them about 1 inch apart, and press an indentation into each one.

3-Chill the shaped cookies for 15 minutes. Preheat your oven to 180°C (fan 160°C, gas mark 4) and bake the cookies for 8 minutes or until set. Cool them on the trays before transferring to wire racks. For the ganache, heat 70ml double cream until hot but not boiling, pour it over 125g finely chopped dark chocolate, and let it stand for 1 minute. Stir in 1 tsp instant coffee and 1 tsp golden syrup until smooth, then fill the cooled cookie indentations with this mixture. Finally, chill the filled cookies for 15 minutes before serving.