Preheat oven to 350 degrees and line 2 baking sheets with parchment paper or silicone mats.
In a large bowl or stand mixer, beat the butter until soft and creamy, about 2 minutes. Add the sugars and continue beating until the mixture is light and fluffy; 2-3 minutes.
Add the eggs and vanilla and beat until smooth.
In a separate bowl, mix together flour, baking soda, salt and ground cinnamon until well combined. Add to the butter mixture and stir together until combined.
Add the oats and raisins and stir until well incorporated.
Using a large cookie scoop, place cookies on prepared baking sheets about 2 inches apart.
Bake cookies for about 12 minutes, until edges just barely start to brown. Remove from oven and let rest on pans for about 10 minutes. Then transfer to wire racks to cool.
Notes
If you aren't a fan of raisins, feel free to use chocolate chips or cranberries.