Preheat to 375°F; whisk flour, salt, and baking soda; line sheets.
Brown butter until golden (1–2 min after foaming); stir in cinnamon.
Whisk brown sugar, granulated sugar, and oil into butter; add egg, yolk, and vanilla.
Stir in flour mixture, then fold in oats and raisins.
Portion 20 (3 Tbsp) mounds; flatten to 2½″ disks.
Bake 8–10 min per sheet; cool 5 min on sheet, then transfer to rack.