In a large mixing bowl, combine butter and sugar. Mix for 3-4 minutes or until it’s pale and fluffy.
Add vinegar and mix until combined. Add the egg until combined. Scrape down the sides of the mixing bowl. Add vanilla and red food coloring and combine.
Then add 1/2 cup of the flour, cocoa, cornstarch, baking powder and salt. Scrape down the sides and the bottom of the mixing bowl. Once fully combined, add the rest of the flour and mix until everything is incorporated.
Mix in the Oreos.
Preheat the air fryer to 350 °F
Place the dough in a Pyrex dish that will fit in your air fryer or in any air fryer safe dish, about 1-1 1/2 inches thick (or however thick you want it to be). Be sure to spray the dish with oil. If you have leftover dough, you can form it into cookie dough balls.
Place the dish in the air fryer basket and cook for 10-12 minutes at 320 °F, or until the dough comes out clean with a toothpick. Then, let the bars rest inside the warm air fryer basket for two or so minutes.
Remove the air fryer and let cool slightly before adding the frosting.
Put softened cream cheese and butter in a bowl, along with the powdered sugar, vanilla extract, and some salt to taste, and blend it all together with a hand mixer. If you don’t like the consistency, you can always add in 1-2 tablespoons of milk to thin it out a bit or add in more powdered sugar to thicken the frosting up to your liking.
Notes
You can make cookies instead of bars- just form them into dough balls and cook for 8 minutes or until they are done to your liking at 320 degrees F or 160 degrees C.