Preheat oven to 350 degrees F (175 degrees C). Grease baking sheets.
In a medium bowl, whisk together the flour, baking soda, cinnamon, and salt. Set aside.
In a large bowl, cream together the butter and brown sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla. Gradually stir the dry ingredients into the creamed mixture.
Stir in the oats until evenly distributed. Drop by tablespoonfuls onto the prepared baking sheets.
Bake for 10 to 12 minutes in the preheated oven, until golden brown. Let cool on baking sheets for a few minutes before transferring to wire racks to cool completely.
Interesting Facts
Oatmeal cookies are one of the oldest types of cookies, dating back to the 1700s.
Oatmeal cookies are often associated with Scotland, since oats are a staple crop in the Scottish diet.
Oatmeal cookies are a popular choice for those trying to eat a healthier diet since oats are a good source of fiber.