Preheat oven to 170 degrees celsius (fan-forced). Line two baking trays with baking paper and set aside.
Insert the butterfly into the Thermomix bowl.
Add the softened butter, brown sugar and caster sugar. Mix on Speed 4, 2 minutes (scraping down the sides of the bowl occasionally).
Add the peanut butter, egg and vanilla extract and mix again on Speed 4, 1 minute.
Remove the butterfly.
Add the plain flour and bi-carb soda. Mix on Speed 4, 10 seconds.
Add the quick oats, M&Ms and chocolate chips and mix on Reverse, Speed 2, 10 seconds (or until combined).
Roll tablespoon-sized balls of the mixture and place onto the prepared trays. Press down slightly.
Bake for 10 minutes or until just starting to turn slightly golden on the very outside (do no overcook).
Allow to cool for 10 minutes on the trays before transferring to a wire rack to cool completely.