In a large bowl, use a rubber spatula to combine the butter, shortening and sugar. Stir in the egg and vanilla until well combined.
In a separate medium bowl, whisk together the flour and baking soda. Add to the wet ingredients and stir until incorporated. Stir in the macadamia nuts and white chocolate.
Cover the bowl of dough with plastic wrap and refrigerate for several hours or overnight.
Preheat the oven to 350 degrees F. Line baking sheets with parchment paper or spray with nonstick spray.
Scoop out heaping tablespoonfuls of dough and roll into a ball. Set on the baking sheet and gently push down to flatten slightly. Place dough 2½ inches apart as the cookies will spread some. If you make them too large, they will crash into each other while baking, so be careful!
Bake 10 to 12 minutes or until the cookies are set and golden on the edges. Let cool on the baking sheet for 10 minutes before transferring to a rack to cool completely.