In a large bowl, whisk together the melted butter, white sugar, and brown sugar. Add the egg and vanilla extract and whisk until fully incorporated.

In a separate bowl, whisk together the flour, baking soda, baking powder, and salt to the bowl. Add to the butter/sugar mixture and fold just until all the flour is incorporated. Lastly, fold in the white chocolate and macadamia nuts.

Scoop all the cookie dough out with a cookie dough scoop, using about 1 ½ tablespoons of dough per cookie onto a prepared baking sheet. Cover the baking sheet and refrigerate for 1 hour.

Preheat the oven to 350℉. Line 3 large baking sheets with parchment paper.

After the dough has chilled, arrange the scoops on a parchment paper-lined baking sheet. Leave at least 2 inches between each cookie for spreading room.

Bake the pans of cookies one at a time in the preheated oven for 10-14 minutes or until the cookies are lightly golden around the edges and the tops are no longer wet. Add additional macadamia nuts and white chocolate to garnish, if desired. Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to finish cooling. Bake the remaining cookies. Enjoy!