Preheat the oven to 425°F (204°C). Line a large baking sheet with parchment paper or a baking pan and set aside.

In a large mixing bowl, whisk together the flour, granulated sugar, baking powder, and salt. Add the cold cubed butter and use a pastry cutter or fork to cut it into the dry ingredients until you have small pea-sized crumbs.

In a separate mixing bowl, whisk together the heavy whipping cream, egg, and vanilla extract until fully combined. Add the wet ingredients to the dry ingredients and stir until just combined. The mixture may be a little crumbly at this point, this is okay! Stir in the chopped macadamia nuts and white chocolate chips.

Place the baking sheet or baking pan in the freezer for 5-10 minutes or until the scones are chilled.

Brush the tops of each scone with a little heavy whipping cream. If you're not adding a glaze, you can top them with coarse sugar if desired.

Bake at 400°F (204°C) for 18-22 minutes or until the tops of the scones are lightly browned and cooked through. Remove from the oven and allow to cool completely.

In a medium-sized mixing bowl, whisk together the powdered sugar, milk, and vanilla extract until well combined. If the glaze is too thick add more milk to thin it out and if the glaze is too thin add more powdered sugar to thicken it.