1: Preheat the oven to 200°C/Fan 180°C/Gas 6.

2: Using an electric whisk, beat the butter and both sugars together in a large bowl until smooth and creamy. Scrape the sides of the bowl with a rubber spatula. Add the egg and vanilla extract and beat again.

3: Add the cocoa and oats to the mixture and stir together to combine. Lastly, add the flour, salt, baking powder and chocolate chips and mix well to form a dough.

4: Divide the dough into 12 equal pieces and shape into balls. Place on a large baking tray, leaving space in between. Using the base of a ½ tsp measuring spoon, create a little hollow in the middle of each cookie by pressing it down on top of each one.

5: Bake on the middle shelf of the oven for 10 minutes, then take the tray from the oven and pop a couple of milk chocolate buttons in each hollow. Return the cookies to the oven for 4–5 minutes.

6: Transfer the cookies to a wire rack and leave to cool slightly before eating.