Preheat the oven to 350°F (175°C). Set racks in the upper and lower thirds. Lightly butter or use ungreased baking sheets.
In a large bowl, beat the unsalted butter, granulated sugar, and light brown sugar with a mixer on medium speed until light and fluffy, 2–3 minutes.
Beat in the large eggs one at a time until smooth, then mix in the vanilla extract. Scrape down the bowl.
In a separate bowl, whisk together the all-purpose flour, baking soda, fine salt, and ground cinnamon.
Add the dry ingredients to the butter mixture and mix on low just until no dry flour remains.
Fold in the old-fashioned rolled oats and raisins until evenly distributed.
Let the dough rest at room temperature for 20–30 minutes to hydrate the oats and firm slightly.
Scoop 1.5-tablespoon portions of dough (about 30 g) onto the baking sheets, spacing about 2 inches apart (12 per sheet).
Bake 10–12 minutes, rotating the sheets front to back and top to bottom halfway through, until edges are set and lightly golden and centers look just set but still soft.
Cool on the baking sheets for 5 minutes, then transfer cookies to a rack to cool completely, 15–20 minutes. Repeat with remaining dough.