Preheat your oven to 160 degrees and line two trays with baking paper.
Place the softened butter and sugar into your Thermomix bowl and mix for 3 minutes, speed 3 to combine.
In the meantime, break the milk chocolate into pieces and place into a microwave safe bowl. Cook for 30 seconds spurts until just melted. Set aside until needed.
Add the flour, bicarb soda, cocoa vanilla extract, egg and melted chocolate and mix for 10 seconds, speed 4 to combine.
Scrape down the sides of your Thermomix bowl and mix for a further 5 seconds, speed 4.
Add the chopped Caramilk chocolate and use your spatula to stir through.
Place the bowl with the mixture into the fridge for 30 minutes to chill, this will help to make scooping up the mixture easier.
Use a dessert spoon to scoop up the mixture and roll into balls. Place them onto your prepared baking trays making sure that you allow room for the cookies to spread,
Bake for 12-15 minutes or until slight cracks have formed
Cool on the baking trays for 5 minutes before carefully transferring to a wire rack to cool completely.