Cream the butter and sugars: In a bowl, beat softened butter with brown sugar and granulated sugar until light and creamy, about 1–2 minutes. This step builds structure and helps with spread.

Add egg and vanilla: Mix in the egg and vanilla until smooth and fully combined. Scrape down the bowl so everything blends evenly.

Whisk dry ingredients: In a separate bowl, whisk flour, baking soda, cinnamon, and salt. Add this to the wet mixture and mix just until you no longer see dry flour.

Fold in oats and raisins: Stir in the rolled oats and raisins (and nuts, if using). If the dough looks crumbly or too stiff, add milk 1 tablespoon at a time. You want a thick, scoopable dough that holds together.

Chill briefly (optional but helpful): Chill the dough for 15–20 minutes for tidier shaping and slightly thicker cookies.

Prep the air fryer: Cut a piece of parchment to fit your air fryer basket. Poke a few holes if not perforated. Lightly grease the parchment to prevent sticking. Preheat the air fryer to 320°F (160°C) for 3 minutes if your model allows.

Portion the dough: Scoop 1 1/2 to 2 tablespoons of dough per cookie. Roll into balls, then flatten slightly to about 3/4-inch thick. Space them at least 1 inch apart in the basket; you’ll likely fit 4–6 cookies per batch.

Air fry: Cook at 320°F (160°C) for 7–9 minutes until edges are set and lightly golden. Centers should look slightly underdone—they’ll firm up as they cool.

Cool: Let cookies rest in the basket on the parchment for 3–4 minutes, then transfer to a rack to cool completely. Repeat with remaining dough.

Tweak for your air fryer: If cookies brown too fast, lower the temp to 300–310°F and add a minute. If they’re pale and too soft, add 1–2 minutes.