M&M Cookies

Beat together the butter (200g) and sugars (90g soft dark brown sugar and 110g caster sugar), until light in colour - this will take 2-3 minutes in an electric mixer.
Add the egg (1 whole large egg and 1 egg yolk) and the vanilla extract (1 tbsp) and beat until combined.
Sift in the dry ingredients (300g plain flour, 1½ tsp bicarbonate of soda and ⅛ tsp salt) and mix together until combined.
Finally, mix in the chocolate chunks (100g).
Divide the mixture in 20. Roll each piece of dough into a ball and then flatten it slightly, so it's about 1½cm thick. Place it onto a baking tray lined with greaseproof paper or a non-stick baking liner. Ensure the cookies are well spread out as they'll double in size in the oven. Gently push about 7 M&Ms into each cookie - Take a look at the picture below the recipe for how the cookies should look on the tray.
Loosely cover the trays and chill in the fridge for at least an hour (up to 5 days).
Once the cookies have chilled, pre-heat your oven to 190°C/170°C fan.
Bake your cookies for 8-9 minutes, so they're golden around the edges but still pale in the middle. You might find it useful to turn the tray after about 7 minutes to help them cook evenly.
Once baked, remove the tray from the oven and leave the cookies to cool on the tray for about 10 minutes before moving them to a wire rack to cool completely.
Enjoy!