Mix Dry Ingredients: In an air-fryer-safe mug or ramekin, whisk together the flour, sugar, cocoa powder, and baking powder.
Add Wet Ingredients: Pour in the milk and melted butter. Stir with a fork until smooth and well combined.
Add Chocolate Chips: Drop chocolate chips into the center of the batter for a molten middle.
Air Fry: Place the mug in the preheated air fryer at 320°F (160°C) and cook for 5 minutes.
Serve: Let it cool for 1 minute, top with a scoop of vanilla ice cream, and enjoy warm!