In a medium saucepan over medium heat, melt the butter. Continue cooking, stirring constantly, until it foams and turns golden brown. You’ll see brown specks at the bottom and smell a nutty aroma — that’s when it’s done! Remove from heat and let cool slightly.

Pour the browned butter into a large mixing bowl. Add the brown sugar and granulated sugar. Mix until smooth and glossy. Let it cool for about 10 minutes so it doesn’t scramble the eggs in the next step.

Add in the eggs one at a time, mixing well after each addition. Stir in the vanilla extract. The mixture should be creamy and thick.

In a separate bowl, whisk together the flour, oats, baking soda, salt, and cinnamon.

Gradually add the dry ingredients to the wet ingredients, stirring until just combined. Do not overmix.

Gently fold in the white chocolate chips and semi-sweet chocolate chips until evenly distributed throughout the dough.

Cover the bowl with plastic wrap and refrigerate the dough for at least 30 minutes (or up to 24 hours). This step helps prevent spreading and enhances flavor.

Preheat your oven to 325°F (163°C) and line two baking sheets with parchment paper.

Use a cookie scoop or tablespoon to scoop out balls of dough. Place them 2 inches apart on the prepared baking sheets. Bake for 11–13 minutes, or until the edges are golden and the centers are just set.

Allow the cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.