Whisk the flour, cinnamon, baking soda, and salt in a large bowl.

In another bowl cream together butter, brown sugar, and granulated sugar. Add the egg and vanilla extract and mix until fully combined.

Slowly mix in the flour mixture and continue mixing until just combined, then mix in the oats and raisins until fully combined, making sure to scrape down the sides of the bowl as needed.

Meanwhile, preheat the oven to 350°F. Line two large baking sheets with parchment paper or silicone baking mats and set aside.

Scoop the cookie dough onto the baking sheets using a 2-inch cookie scoop, and press down slightly. Leave room between cookies to allow for spreading.

Bake for 10-12 minutes or until the edges of the cookies are lightly golden brown. Cool on the baking sheet for 5 minutes, then transfer the cookies to a wire rack to finish cooling.

Cookies may be stored on the counter in an airtight container for up to five days.