Melt the butter in the microwave and then pour into a mixing bowl.
Add the Brown Sugar and Sugar and whisk until combined.
Add in the egg and egg yolk and then whisk until fluffy. Then add in the vanilla extract and salt and mix until combined.
Sift in the plain flour and baking soda and fold in until you get a cookie dough consistency.
Crush 6 cookies and cream biscuits and add into the cookie dough as well as the white chocolate chips.
Use a medium sized ice cream scoop or measure 50g dough balls (3 tbsp) and place onto a lined baking tray.
Spread a little cookies and cream spread onto the cookie dough (you can use white chocolate if that's easier to find). Then place into the fridge to chill for at least 30 mins.
Pre-heat the oven to 180°C and then place the baking tray into the oven for 11 mins.
Be sure to space out the dough balls as they will spread in the oven.
Allow the cookies to rest for a while before transferring them to a wire rack to cool fully.
