Chop the 24 Oreos into roughly 1/2-inch pieces, separating some whole pieces for topping if desired. Have all ingredients measured and ready before you begin cooking, as the melting and mixing process moves quickly. This prep work ensures you won't be scrambling while the batter comes together.

Combine the unsalted butter and 2 1/4 cups semi-sweet chocolate chips in a microwave-safe bowl. Microwave in 30-second intervals, stirring between each interval, until completely melted and smooth (usually 1-2 minutes total). Be careful not to overheat—chocolate can scorch easily. I prefer to remove the bowl when the mixture is about 80% melted and stir gently to let residual heat finish the job, which prevents any burnt flavor.

Add the sugar, room-temperature eggs, and vanilla extract to the melted chocolate mixture from Step 2. Whisk vigorously until well combined and slightly thickened, about 1-2 minutes. The eggs should be at room temperature so they incorporate smoothly without creating lumps or cooling the chocolate too much.

In a separate bowl, whisk together the all-purpose flour, cocoa powder, salt, and espresso powder. Fold this dry mixture gently into the chocolate batter from Step 3 using a spatula or wooden spoon until just combined—don't overmix, as this keeps the brownies fudgy rather than cake-like. I like to add the espresso powder here because it deepens the chocolate flavor without making the brownies taste like coffee.

Grease a 7-inch or 8-inch round air fryer-safe baking pan or similar size pan that fits your air fryer. Pour half of the batter from Step 4 into the prepared pan and spread evenly. Distribute the chopped Oreos from Step 1 over this base layer, then pour the remaining batter on top, spreading gently to cover the Oreos. This layering ensures Oreos are distributed throughout rather than sinking to the bottom.

Place the baking pan in the air fryer basket and set the temperature to 320°F. Air fry for 20-25 minutes, checking around the 20-minute mark by inserting a toothpick near the center—it should have a few moist crumbs clinging to it but not be wet batter. Remove from the air fryer and let cool for 5-10 minutes before slicing and serving warm. The brownies will continue to set slightly as they cool.