Grease 2 ramekins with cooking spray. Set aside.
In a bowl, add the flour, sugar and coconut oil and mix until crumbly.
Add baking powder, spices and salt and stir to combine.
In the bottom of both prepared ramekins, place a little layer of flour mixture.
Divide plum slices into the ramekins and top with flour mixture.
With a piece of foil, cover each ramekin.
Slide the Air Fryer Basket inside and adjust the temperature to 350 °F to preheat for 5 minutes.
After preheating, arrange the ramekins into the Air Fryer Basket.
Slide the basket into Air Fryer and set the time for 22-24 minutes.
After 20 minutes of cooking, remove the foil pieces from the ramekins.
After cooking time is finished, remove the ramekins from Air Fryer and place onto a wire rack to cool for about 10 minutes.
Serve warm.