Preheat oven to 350°F (175°C) and line baking sheets with parchment paper.

In a large bowl, cream together softened butter, brown sugar, and granulated sugar until light and fluffy.

Beat in eggs one at a time, then stir in vanilla extract.

In a separate bowl, whisk together flour, baking soda, salt, and cinnamon.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Fold in the rolled oats and chocolate chips.

Scoop rounded tablespoons of dough (about 2 tablespoons each) onto prepared baking sheets, spaced 2 inches apart.

Bake for 10 to 12 minutes, or until edges are golden brown but centers still look slightly underbaked.

Let cookies cool on the baking sheet for 5 minutes before transferring to a wire rack.