Sieve the flour into a bowl. Coat the blackberries in the flour, then shake off the excess flour and put the fruits on a plate.
Add the other dry ingredients to the flour and combine.
In another bowl combine the egg, milk, vanilla and melted margarine, then add this mixture to the flour.
Combine gently until you get a smooth batter, then fold in the grated apples and the coated blackberries.
Fill about 6 silicon cases with the batter then put as many as you can in the air fry basket(s).
Mix some sugar with cinnamon and scatter a pinch or two on top of each muffin.
Set the air fryer to bake - this should be about 10-15 minutes at 200°C.
Look at the muffins after 10 minutes - if they are golden brown and a sugar has caramelized on the top, they are ready. If not, bake them for another couple of minutes, until golden.
Let them cool in the basket for 5 minutes, then transfer them to a wire rack.
Let them cool completely before serving.