Brown the butter by melting unsalted butter in a medium saucepan over medium-low heat for 5-7 minutes until deep chestnut brown and nutty aroma develops.

Mix sugars by adding light brown sugar and granulated sugar to the browned butter and stir until smooth, then chill for 10 minutes.

Preheat the oven to 325°F (163°C) and prepare two baking sheets lined with parchment paper.

Combine wet ingredients by adding eggs and vanilla extract to the chilled sugar-butter mixture and mix until smooth.

Mix dry ingredients in a separate bowl and whisk flour, oats, baking soda, kosher salt, and cinnamon together, then incorporate into the wet mixture.

Add chocolate chips by gently folding in white and semi-sweet chocolate chips into the dough.

Shape cookies by dropping rounded balls of dough on baking sheets, spaced 2 inches apart.

Bake cookies for 11-13 minutes until golden brown edges and soft centers, then cool before transferring to wire racks.