Cut a piece of greaseproof to about the same size as the base of your tray. Fold it in half 3-4 times to create a thin triangle. Make holes with a skewer or hole punch and unfold.

Put the butter and sugar in a large bowl and mix until fluffy.

Add the milk, egg  and vanilla extract and whisk together.

Sift in the flour, add the oats and fold to combine.

Add the raisins and mix again.

Divide your dough into 20 portions of dough, rolled into balls. You can eyeball this, or if you want to be super accurate, you can divide the dough into 20 x 34g portions.

Place 4-5 at a time into your lined tin, spaced apart to allow them to spread.

Set the air fryer to 140C/285F and bake the cookies for 15 minutes until golden.

Cool briefly on the tray to allow them to firm up, then transfer to a cooling rack with a spatula.