Preheat oven to 350 degrees. Line a cookie sheet with parchment paper or a baking mat, set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat together butter, sugars and vanilla extract (about 2 minutes until nice and fluffy). Add in egg, mix, then egg yolk, mixing until just combined.
In a medium size mixing bowl, combine flour, baking soda, baking powder, cornstarch and salt, whisk to combine. With mixing speed on low, gradually add the dry ingredients, mix until just combined. Remove bowl from stand and fold in coconut, toasted coconut, white chocolate chips and chopped macadamia nuts. NOW- you can either bake the dough right away, or allow it to chill overnight (which I did).
Scoop dough onto prepared sheets using a standard size cookie scoop. Place in oven and bake for 10-12 minutes or until the edges become lightly golden brown in color. The centers might still look soft, but that’s ok, you don’t want to overbake these or they’ll be hard! Allow to cool on sheet for 3 minutes before transferring to a wire rack to cool completely.