1. Add the butter and peanut butter to a large bowl and mix until well combined. Add the sugars and mix until light and creamy. Next, add the baking soda and mix it in. Add the eggs one after another and mix in well. Add the vanilla extract and mix it in. Finally, add the oats, chocolate chips and M&M’s and mix in until combined. Place in the fridge for at least 1 hour.

2. Preheat the oven to 180°C (350°F). Line a baking sheet with baking parchment. Place about two tablespoons of dough for one cookie on the baking sheet and leave plenty of space in between. The cookies spread quite a bit (I got 5-6 cookies on one baking sheet). Bake the cookies for about 15-18 minutes – the edges should have some color. Take them out of the oven and let them cool down on the baking sheet until you can move the cookies without them breaking. Transfer them to a wire rack and let them cool down completely. Repeat with the remaining dough.