Place the softened butter, brown sugar and caster sugar into your Thermomix bowl and mix for 30 seconds speed 3.
Scrape down the sides of the bowl and mix for a further 20 seconds, speed 4 or until light and creamy.
Scrape down the sides of the bowl and add the plain flour, bicarb soda, eggs, vanilla extract and salt and mix for 10 seconds, speed 4.
Scrape down the sides of the bowl and add the chocolate chips. Select the 'kneading/dough' function and mix for 30 seconds or until a soft dough forms.
Scoop up the mixture and roll into walnut-size balls and place onto the prepared baking trays and flatten slightly. Make sure to leave a 3cm gap between each chocolate chip cookie as they will spread a little. Repeat until you have used all of the mixture.
Place your chocolate chip cookies into the oven and bake for 18-20 minutes or until the tops begin to turn golden brown. Carefully remove the chocolate chip cookies from the oven and after 5minutes transfer them to a wire rack to cool completely.