In a large bowl, whisk together the flour, cinnamon, baking soda, and salt. Set aside.
In a stand mixer bowl fitted with a paddle mixer, cream together the butter, brown sugar, and granulated sugar for 1-2 minutes, until combined. Add the egg and vanilla extract, and mix until fully combined.
Slowly mix in the dry ingredient mixture and continue mixing until just combined, then mix in the oats and raisins until combined, scraping down the sides of the bowl as needed.
Cover the cookie dough with plastic wrap and refrigerate for 30 minutes.
Meanwhile, preheat the oven to 350F.
Line two large baking sheets with parchment paper or silicone baking mats, and set aside.
Once chilled, remove the dough from the refrigerator. Using a 2 tbsp. Cookie scoop, scoop the dough onto the prepared cookie sheets.
Bake in separate batches at 350F for 10-12 minutes, or until the cookie edges are golden-brown and the top is set.
Remove from the oven, and let cool for five minutes. Transfer to a cookie sheet to cool completely.