Prepare the Cookie Dough : Preheat the oven to 350°F (175°C) and line baking sheets with parchment paper. In a large bowl, cream together softened butter, brown sugar, and granulated sugar until light and fluffy (about 2–3 minutes). Beat in the eggs, one at a time, then stir in vanilla extract. In a separate bowl, whisk together flour, baking soda, cinnamon, and salt. Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Fold in oats, raisins, and optional nuts.

Shape and Bake : Using a cookie scoop or spoon, drop dough balls (about 2 tablespoons each) onto prepared baking sheets, spacing 2 inches apart. Flatten slightly with the back of the spoon or your fingers for even baking. Bake for 10–12 minutes, until the edges are golden but the centers remain soft. Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.