Preheat the oven to 180 degrees Celsius. Line a cookie sheet with baking paper and set aside.
In a large mixing bowl, sift the flour, baking soda and sea salt and mix to combine.
In a separate bowl, add the melted butter with the sugar and mix very well. Add the egg and vanilla extract and stir until fully incorporated.
Add the dry mixture to the wet mixture and mix well. Stir through the macadamia nuts and white chocolate chunks.
Using your hands, roughly form golf ball sized cookies and place on the cookie sheet. Using a fork or the back of a spoon, press down lightly on each cookie. Ensure cookies are well spaced apart as they expand. Bake in the oven for 12-15 minutes, until slightly golden on top.
Remove from oven and allow to cool completely on baking tray.
Cookies can be kept in a sealed container for up to 2 weeks. For crispier cookies (as pictured), remove from oven when golden on top.