Preheat your oven to 180°C (350°F) and line a large tray or two with baking paper. For fan/convection ovens, the temperature is 160℃/320℉.
In a large bowl, mix together the butter, caster sugar, and brown sugar.
Stir in the egg, vanilla extract and pink food colouring.
Add the strawberry Nesquik powder and the self-raising flour. Mix well then use your hands to press everything together into a ball.
Gently press the chocolate chips into the dough.
Divide the dough into 12 equal-sized pieces and roll into balls. Place them onto your baking tray, leaving a few inches of space in between to allow for spreading.
Bake for 11-12 minutes until the cookies are firm around the edges. They should look soft in the middle but not wet.
Top with extra white chocolate chips while the cookies are still warm.
Let them cool completely on the tray then enjoy!