You can easily turn oatmeal raisin cookie dough in oatmeal cookie bars! Line a 13 x 9-inch baking pan with parchment or lightly grease with cooking spray. Press the dough evenly into the bottom of the pan. Bake at 350 degrees for 30 to 35 minutes or until lightly golden on top. Set the pan on a wire rack to cool completely. Cut into bars and serve.