Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

Melt the unsalted butter in a microwave-safe bowl until it's bubbly and slightly browned. Let it cool.

In a large mixing bowl, combine the melted butter with granulated sugar and mix well. Add eggs one at a time, followed by the vanilla extract, stirring until fully combined.

In another bowl, whisk together the all-purpose flour, cocoa powder, and baking powder until well combined.

Gradually add the dry mixture to the wet mixture, stirring until just combined. Be careful not to over-mix.

Gently fold in the chopped Oreos, distributing them evenly throughout the dough.

Using a cookie scoop or spoon, drop generous amounts of the dough onto your prepared baking sheet, leaving sufficient space between each cookie.

Bake for about 10-12 minutes until the edges are set but the centers are still slightly soft. They will firm up as they cool.

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