Preheat the oven to 350°F (175°C) and line an 8x8 inch baking pan with parchment paper. Set aside.

In a microwave-safe bowl, melt the butter, oil, and both sugars together in 30-second intervals, mixing after each time. Once melted completely, microwave for another minute and stir vigorously to help the sugar dissolve.

Using a mixer, whisk in the eggs one at a time and then add the vanilla extract. The batter should start to pull away from the bowl slightly.

Gently fold in the flour, cocoa powder, and salt until just combined.

Pour half of the brownie batter into the prepared baking pan and spread it evenly.

Place the Oreos in the center of the batter, then top with the remaining brownie batter, spreading it to cover the Oreos completely.

Crush the extra 5 Oreos and sprinkle them on top.

Bake in the preheated oven for 30 minutes.

Let the brownies cool completely on a wire rack before slicing.