Copycat DoubleTree Chocolate Chip Cookies

Preheat oven to 350°. Line two baking sheets with parchment. In a large mixing bowl using a hand mixer, cream butter, sugars, and vanilla until light and fluffy, about 5 minutes. Slowly mix in eggs, beating until mixture is smooth. In a separate bowl, combine flour, baking soda, salt, and cinnamon. Gradually stir dries into the butter-sugar mixture, then fold in oats, chocolate chips, and walnuts. Use a large cookie scoop to place balls of dough about 2" apart on prepared baking sheets. Bake until edges are lightly golden but center of cookie is still a bit soft, 17 to 19 minutes.