In a mixing bowl, combine the flour, baking soda, baking powder, and salt. Whisk to combine. Set aside.
In the bowl of a stand mixer, add the butter, brown sugar, and white sugar and cream together until smooth, about 2-3 minutes.
Add in the egg and vanilla and mix until well incorporated. Add in the flour mixture and blend until just combined. Fold in the white chocolate chips and macadamia nuts.
Using a tablespoon-size cookie scoop, portion the dough onto a parchment-lined baking sheet. Gently flatten the balls of dough to form an even disk. Bake for 9-11 minutes or until just set and slightly brown around the edges.
Cool on the baking sheet for 2-3 minutes before transferring to a rack to cool completely. Store in an airtight container.
Notes
Walnuts can be substituted for macadamia nuts.
To freeze the dough, portion balls of dough onto a parchment-lined baking sheet. Freeze until firm, then transfer them to a freezer-safe bag. Store for up to 2 months. Thaw in the fridge or bake from frozen. If baking frozen, allow a few extra minutes of baking time.
To freeze cookies, cool the cookies completely. Freeze on a sheet pan until firm. Transfer them to a freezer-safe bag and store them for up to 2 months. Thaw at room temperature.