Ideally using a stand mixer with the paddle attachment, mix the butter and dark brown soft sugar together until fluffy and paler in colour. This will take 3-5 minutes in an electric mixer (I use speed 3)
Add the egg and vanilla extract and mix in
Add the plain flour, ground ginger, mixed spice, baking powder, bicarbonate of soda and salt and mix them in until just combined
Then mix in the dark chocolate chips and stem ginger briefly, just to evenly distribute them
Divide the dough into portions, I weighed the dough out to make each cookie an equal size (they were roughly 80g each)
Roll the dough portions into balls using your hands, place them on either a lined baking tray, or into a tupperware container lined with baking paper. Chill them in the fridge for 30 minutes
Meanwhile, pre-heat your oven to 180C Fan/400F/Gas Mark 6
After the 30 minutes is up and your oven is pre-heated, place the dough balls onto lined baking trays, leaving space (at least 2") between them to spread. If you don't have enough baking trays, keep the dough in the fridge and bake the cookies in batches
Bake for 12 minutes, remove from the oven and leave the cookies to cool for at least 10 minutes on the baking trays before moving to a cooling rack
Enjoy warm, or once fully cooled. Store leftovers in an airtight container and eat within 3 days
Notes
Make sure all your ingredients (particularly the butter and egg) are at room temperature before you start baking.
I prefer to use unsalted butter for this recipe, but you can also use a baking spread. Baking spreads do contain more water, so your cookie dough could be looser.
I highly recommend using dark brown soft sugar for these cookies, not only for delicious flavour but they give the cookies their gorgeous golden colour. You could use light brown soft sugar, or a mix of light brown soft sugar and caster sugar, but the colour of the cookies will be lighter.
Mixed spice is a British spice blend containing cinnamon, coriander seed, nutmeg, clove, pimento, and ground ginger. If you can't get hold of it where you're based, you can use a Pumpkin Spice mix instead or add a mix of other spices - I recommend cinnamon and nutmeg.
For me, dark chocolate and ginger belong together, but you can use milk or white chocolate for these cookies if you prefer.
Although I provide cup measurements, I highly recommend weighing your ingredients out using digital kitchen scales. It is the most accurate way to measure ingredients and will ensure the best results. Digital scales are very low cost and can be purchased for around £12 ($16.50).
For teaspoon (tsp) and tablespoon (tbsp) measurements, please use measuring spoons and not the type of spoons you eat with. Again this will ensure accuracy and provide the best results.