TIP: When they come out of the oven and are still hot, you can re-shape each one into a perfect circle. Take a large, flat-edged cookie cutter that is slightly larger than the cookie and move it in a circular motion around the cookie, for a neat circle.
125g of unsalted butter, softened
175g of soft light brown sugar
100g of caster sugar
½ tsp of sea salt flakes, plus extra for sprinkling
2 tbsp of coffee granules mixed with 2 tbsp of boiling water (leave to cool slightly) or 2 tbsp of espresso (cooled)
1 tsp of vanilla paste (optional, if you have some)
300g of plain flour
½ tsp of baking powder
200g of dark chocolate, chopped into chunks (or use chocolate chips)
Preheat the oven to 190°C/170°C Fan/Gas 5 and line two large baking trays with baking paper or a silicone mat.
Beat together the butter, both sugars and sea salt flakes in a large bowl with an electric whisk for 4-5 minutes until creamy, pale and smooth (or beat by hand with a wooden spoon if you’re feeling strong). Beat in the egg, coffee and vanilla and mix again (don’t worry if it looks split at this stage). Tip in the flour and baking powder and mix until you have a thick, pliable mixture. Fold in the dark chocolate.
Take 50g of the mixture (you can weigh each one to be accurate or weigh one and eyeball the rest) and roll it into a ball. Repeat with the rest of the dough.
Place onto the prepared baking trays, leaving about 6cm space between them. With the palm of your hand, gently press down on each one until they’re around 1cm/½in thick, then sprinkle with a few sea salt flakes. Once pressed, you can bake them at this point, or cover and keep them in the fridge for up to a week, or in the freezer for up to 3 months.
Bake for 10-12 minutes until golden brown. Leave to cool slightly on the baking trays, then transfer to a wire rack and leave to cool completely. Sprinkle with a little extra flaky salt if you like. Tuck in and enjoy! Cook unbaked ones from the fridge for 12-14 minutes and cook from frozen for 13-15 minutes. Store in an airtight container for up to 4 days.