In a large bowl with electric mixer, beat together the butter, brown sugar, and granulated sugar until well combined.
Add the egg and vanilla and beat until combined.
Add the cinnamon, baking soda, and salt, and beat until combined.
Add the flour, beating until combined.
Add the oats, beating until combined.
Fold in the chocolate chips.
Cover and chill in the refrigerator for 30-60 minutes.
Preheat the oven to 350 degrees F.
Line a baking sheet with parchment paper.
Roll the dough into 1" balls and place on parchment paper lined baking sheets. Bake for 10-12 minutes, until edges are slightly golden.
Let cool for about 5 minutes and then transfer to cooling rack to cool completely.
Enjoy!