Preheat the oven to 375°F and line two baking sheets with parchment paper or silicone mats.
In a large bowl, beat the butter with both sugars until light, smooth, and creamy.
Mix in the eggs and vanilla, beating until the mixture looks fluffy and well combined.
In a separate bowl, whisk together the flour, baking soda, cinnamon, and salt.
Slowly add the dry ingredients to the butter mixture and mix just until combined.
Stir in the rolled oats and raisins evenly throughout the dough.
Drop spoonfuls of dough onto the baking sheets, spacing them about 2 inches apart.
Bake for 8–10 minutes, rotating the pans halfway, until the cookies are lightly golden.
Let the cookies rest on the baking sheet briefly, then transfer to a wire rack to cool completely.
