Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper.

In a large bowl, cream together the butter, brown sugar, and granulated sugar until smooth and fluffy.

Beat in the eggs one at a time, then stir in the vanilla extract.

In a separate bowl, whisk together the flour, baking soda, cinnamon, and salt. Slowly add this to the butter mixture, mixing just until combined.

Stir in the oats and raisins until evenly distributed.

Drop spoonfuls of dough onto the prepared baking sheets, spacing them about 2 inches apart.

Bake for 10-12 minutes, or until the edges are golden brown and the centers are set.

Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack.