• Whisk together the flour, baking soda and salt in a medium bowl. Set aside.
• In a medium saucepan, melt 12 tablespoons of butter over medium heat, reserving 4 tablespoons, stirring occasionally with a rubber spatula. Once the butter is fully melted, increase the heat to medium-high. Stir constantly until the butter develops a nutty aroma and you see golden brown brown milk solids appear on the bottom of the pan.
• Remove from heat and add the remaining 4 tablespoons of butter. Stir until completely melted. See Note.
• Stir in the brown sugar, granulated sugar and vanilla, then stir in the eggs and sourdough starter.
• Add the flour mixture to saucepan and stir until mostly combined.
• Stir in the macadamia nuts and white chocolate chips until completely mixed in.
• Cover the pan with plastic wrap and chill the dough in the refrigerator for at least 1 hour or up to 48 hours for long fermentation.

When Ready to Bake

• Preheat the oven to 375℉.
• Use a spoon or cookie scoop to make 1½ inch sized cookie dough balls. Place on a baking sheet lined with parchment paper leaving 2½ inches between each cookie.
• Bake for 12-15 minutes. The cookies should appear soft and puffy in the center with golden edges when done. Do not over-bake.
• Cool in cookie sheet for 5 minutes before transferring to a wire rack to cool completely.