In a large bowl, beat the dairy-free spread with a hand-held mixer or stand mixer with paddle attachment until smooth and creamy. Add the brown and white sugars and continue mixing until light and creamy. Mix in egg and vanilla, scraping down the sides of the bowl as needed.

In a separate bowl, sift flour, cornstarch, baking soda and salt and mix together.

Slowly mix the dry ingredients into the wet until combined. The dough will be quite thick. Add the chopped white chocolate and macadamia nuts and mix through the dough with a spatula until evenly distributed. Cover dough and place in the fridge to chill for at least 1 hour.

Preheat oven to 180°C and line 2 trays with baking paper.

Remove cookie dough from the refrigerator and roll dough into balls using about 1.5 tablespoons of dough in each. Place dough balls on the trays about 5 centimeters apart.

Bake for 10-11 minutes, until just golden brown around the edges. They will still be very soft when you take them out of oven. If they are too puffy, gently press down on the tops of them with the back of a spoon. Let cool for 5 minutes on the tray before transfering to a wire rack to cool completely.