Stir together oats, flour, cinnamon, baking soda, and salt. Beat together butter, brown sugar, and granulated sugar in a large bowl with a fork or an electric mixer until light and fluffy. Add egg and vanilla and beat until combined well. Add oat mixture and beat until just combined.
Drop dough by heaping tablespoons 2 inches apart onto baking sheets and flatten mounds slightly with moistened fingers. Bake cookies in upper and lower thirds of oven, switching position of sheets halfway through baking, until golden, about 12 minutes total. Transfer to racks to cool.
Currently trying this recipe from the Wall Street Journal, of all places: http://www.wsj.com/articles/recipe-oatmeal-raisin-cookies-1442345556