Preheat the oven to 375ºF and line two baking trays with parchment paper.
Add the butter and brown sugar to a mixing bowl and beat with an electric mixer until light and fluffy. Be sure to scrape down the sides of the bowl as you mix to incorporate every bit of butter.
1 cup butter, 1 ½ cups brown sugar
Add the eggs, one at a time, beating after each addition. Adding the eggs slowly ensures the batter stay smooth.
2 large eggs, 2 teaspoons vanilla extract
Add the vanilla extract and blend again.
Add the flour, cornstarch, baking soda, and salt to the bowl and mix to make a smooth cookie dough.
2 ¾ cups flour, 2 teaspoons cornstarch, 1 teaspoon baking soda, 1 teaspoon salt
Stir in the macadamia nuts and white chocolate chips by hand.
1 ½ cups chopped macadamia nuts, 1 cup white chocolate chips
Scoop the cookie dough onto the prepared sheet tray. Make each scoop about ¼ cup in size. They should be about 2 inches apart on the tray.
Bake the cookies for 8 minutes. The edges will be golden brown and the tops of the cookies will no longer look wet.
Let the cookies cool on the tray for 10 minutes before moving to a cooling rack. Enjoy while warm!