In a medium sized sauce pan, brown butter on medium - high heat until golden brown, whisking often. Be cautious of splatter. As soon as butter starts to brown, lower temperature and remove as soon as butter is desired color. Cool in refrigerator or freezer until room temperature.

Cream the cooled browned butter in a standing mixer with both sugars for about 30 seconds. Add both eggs. Mix until well incorporated, and then add the baking powder and salt. Give it anther good mix, and then add the flour. Mix until well incorporated, then add white chocolate chips and macadamia nuts. Stir gently until they are mixed in. 

Using a 4 tablespoon measure, scoop cookie dough onto a nonstick baking sheet and bake for 11-13 minutes at 375°F. 

Cool on cookie sheet for five minutes, then transfer to a baking rack to cool completely. Store in an airtight container for 3-4 days. Enjoy!