Preheat oven to 350 deg with a rack in the middle of the oven. Combine butter and sugars and beat until creamy/fluffy (5 minutes). Add egg and vanilla and beat until incorporated. Add flour, baking soda, and salt, and beat until all flour is absorbed (scrape down sides of bowl to get it all). Add oatmeal one cup at a time and stir until mixed. Raisins can be added, but I prefer milk chocolate chips. Or keep it plain if you’d like.

Drop 1/4 cup gobs of dough on either greased baking sheet or baking sheet lined with parchment paper. Dough should be dropped about 3 inches apart (6 fit well on a standard baking sheet). Bake ~18 minutes or until edges are brown and middle is set. Let cool for a couple minutes on sheet then remove cookies and cool more on either a paper towel or wire rack.