Preheat oven to 350°F Line baking sheet with parchment paper or a Silpat.
In bowl of stand mixer using paddle attachment, cream together butter and sugars until smooth and fluffy, about 3-4 minutes on medium high. Add egg and mix just until incorporated. Add vanilla, mixing just until incorporated.
In a separate bowl, whisk together the flour, salt, and baking soda. Gently combine the flour mixture with the butter/sugar mixture until the flour is just mixed inches.
Fold in white chocolate chips and macadamia nuts.
Refrigerate for at least a half hour, or at most 3 days. Make golfball sized balls and flatten a bit, or use a medium sized cookie dough scoop. Sprinkle with sea salt, if desired.
Bake for 12-14 minutes, or just until bottoms of cookies are light golden brown. Cookies may seem soft and underdone, but they will set upon cooling.
Cool 5 minutes on baking sheet and use flat spatula to transfer them onto cooling rack.