Preheat oven to 350°F (175°C) and line baking sheets with parchment paper.
Cream together butter, brown sugar, and granulated sugar until light and fluffy.
Beat in eggs one at a time, then mix in vanilla extract.
In a separate bowl, whisk together flour, baking soda, salt, and cinnamon.
Gradually add dry ingredients to wet ingredients and mix until combined.
Stir in oats and raisins until evenly distributed.
Scoop tablespoon-sized dough balls onto prepared baking sheets.
Bake for 10–12 minutes until edges are golden brown.
Cool on baking sheet for 5 minutes before transferring to a wire rack.
