Preheat oven to 350°F (175°C), line baking sheets.
Mix oats, flour, baking soda, cinnamon, salt.
Combine melted butter, sugars, egg, vanilla.
Fold wet into dry, do not overmix.
Add chocolate chips, raisins, walnuts.
Scoop dough, place 2 inches apart.
Bake 10–12 min until edges golden.
Cool 5 min on sheet, then rack.