Prepare your 7-inch baking pan by generously greasing with butter on the bottom and all sides. Set aside.
Preheat your Air Fryer by setting the temperature to 330 degrees Fahrenheit and allowing it to run for about 5 minutes while you prepare your brownie batter.
Add your all-purpose flour, cocoa powder, sugar, butter, eggs, vegetable oil, vanilla extract, salt, and baking powder into a large bowl and stir until thoroughly combined.
Add it to the prepared baking pan and smooth out the top.
Place in your preheated Air Fryer and bake for 15 minutes or until a toothpick entered in the center comes out mostly clean.
Remove and allow to cool in the pan before removing and cutting.
