In a large mixing bowl, mix the flour, sugar, salt, baking soda, and ground cinnamon.
Pour the milk, egg, melted butter, and vanilla into the mixing bowl, beating until well combined.
Fold in the fresh strawberries, mix well.
Spray your donut pans with olive oil, being careful to spray the sides really well.
Scoop the batter into the donut pans, filling about 2/3 the way full.
Set the pan into the air fryer and set the temperature to 320 degrees F for 10-15 minutes. Test to see if the donut comes out clean, but sticking a toothpick into the center of one, and if it comes out clean, remove it from the air fryer.
Let cool slightly while you make the icing.
To make the icing, add the powdered sugar and milk into a small bowl. Mix until well blended.
Glaze the donuts with the icing, plate, serve, and enjoy!