Preheat the oven to 350 degrees F. Line two large baking sheet with Silpat baking mats or parchment paper. Set aside.

In a medium bowl, whisk together the oats, flour, baking soda, salt, and cinnamon. Set aside.

Using a mixer, beat the butter, peanut butter, and sugars together until creamy, this will take about 2 minutes, on medium speed. Beat in the egg and vanilla extract. Mix until well combined.

On low, add in the dry ingredients and mix until just until the combined.

Scoop the cookies into round balls and place on the prepared baking sheets, leaving 2 inches in between cookies. Bake for 10-12 minutes, or until the cookies are lightly browned around the edges, but still soft in the middle.

Remove cookies from oven and let cool on the baking sheet for about 5 minutes. Transfer to a wire rack and cool completely.