Place butter into a small saucepan over medium heat. Cook and swirl butter in pan to melt butter. Continue to swirl pan while butter bubbles and cooks. Watch carefully as butter browns. When butter is brown, carefully pour into a heat proof bowl, scraping brown bits from pan too. Let butter cool for 30 minutes or you can place in refrigerator for 15 minutes.

Preheat oven to 375 degrees and line a baking sheet with parchment paper. Place brown butter into a large mixing bowl. Stir in brown sugar and granulated, stirring until well combined. Add eggs and vanilla stirring until well combined. Stir in flour, baking soda and salt. Stir until dough forms then add chocolate chunks stirring until combined. You either can scoop regular size cookies, about 2 tablespoons of dough onto your baking sheet 1 inch apart and bake for 10 minutes or scoop heaping 1/4 cup size cookie dough balls shaped into a ball 2 inches apart. Press broken Oreo Cookies pieces into tops and sides of cookie dough balls. Bake for 12-13 minutes. Remove from oven and let cool for 15 minutes before transferring to a serving plate. Right when cookies come out of oven, you can add more broken Oreo Cookies pieces to tops of cookies if done right away.