Pre-heat oven to 350 F. Line baking sheets with parchment paper.

Beat softened butter with brown and granulated sugars in the bowl of a stand mixer (or by hand) together until well combined.

Keeping the motor running, add in one egg, then the extra yolk. Combine well then add the vanilla extract.

Blend in flour, baking soda, cornstarch, nutmeg, and salt. Mix well, scraping down the sides of the bowl as you go.

Stir in white chocolate chips and macadamias.

Scoop a heaped tablespoon of dough and roll it into a ball with your hands. Place onto parchment paper and flatten slightly (slightly wet hands keep dough from sticking) Repeat until there are 12 evenly spaced cookies per sheet.

Bake in a 350 F oven for 10-12 minutes. It's best to underbake them rather than overbake them. Remove and let cool on wire racks.

White Chocolate Drizzle: Microwave 1/2 cup white chocolate chips in 30-second increments. Stir well then place in a plastic freezer bag. When all of the chocolate is in the same corner, snip a tiny part away from the corner and press slightly to drizzle chocolate over cooled cookies. Allow chocolate to set a few hours.