If you want to bake the cookies straight away and not chill them, then pre-heat your oven to 180C Fan/400F/Gas Mark 6 at the start. If you want to chill them, then wait to turn the oven on until they are chilling
Ideally using a stand mixer with the paddle attachment, mix the butter, caster sugar and light 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, cocoa powder, baking powder, bicarbonate of soda and salt and mix them in until just combined
Then mix in the dark chocolate chips briefly, just to evenly distribute them
Divide the dough into portions, I weighed the dough out to make each cookie an equal size
Roll the dough portions into balls using your hands, if you want chunkier cookies then you can chill them before baking them. To do so, 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
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
To decorate, melt the white chocolate. I prefer to do this in a microwave, break the chocolate into chunks and place into a suitable bowl. Blast for 30 seconds, stir, then blast for 10 seconds and stir, repeat until melted. Use a spoon to add the melted white chocolate to the cookies. Add the holly decoration while the chocolate is still wet so that they stick. Place onto baking paper and leave the chocolate to set
Store leftovers in an airtight container and eat within 3 days
Video
Notes
Make sure all your ingredients (particularly the butter and eggs) 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.
I used dark chocolate chips in the cookies, you could use milk chocolate, or omit them entirely if your prefer.
I recommend using light brown soft sugar for delicious flavour and a more gooey cookie, but you can replace it with caster sugar if you can't get hold of brown sugar.
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.