In a large bowl combine butter and sugars. Beat on low speed to medium speed with an electric hand mixer or in a bowl of a stand mixer with the paddle attachment. The batter should look smooth and creamy.
Add egg and vanilla. Mix on low until combined. Set aside.
In a separate large mixing bowl, combine dry ingredients. Whisk to combine and add to wet ingredients gradually. I recommend sifting the dry flour mixture.
Add ½ or 1 measuring cup at a time, beat on low until combined, and then continue with the next batch. Mix until ingredients are almost combined, a few lumps here and there are fine.
Stir in the chocolate chips and chopped macadamia nuts. I recommend chilling the batter for 1 hour in the fridge. Preheat the oven to 350 degrees Fahrenheit.
The batter will resemble playdough and should not be overly sticky after chilling. Scoop 2 tablespoonfuls of batter, rolling it into about 2-inch balls (1 ½ tablespoons).
Arrange the cookie balls on a baking sheet lined with parchment paper at least 2 inches apart. Don’t press down!
Bake for 10-12 minutes (the time varies due to different ovens). Remove from the oven.
While the cookies are still hot press in more chips and nuts on top (optional for pretty presentation) and sprinkle with sea salt flakes.
