Step 1:
Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper or silicone mats.

Step 2:
In a large mixing bowl, cream together the softened butter, brown sugar, and granulated sugar until smooth and fluffy, about 2–3 minutes.

Step 3:
Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.

Step 4:
In another bowl, whisk together the flour, baking soda, cinnamon, and salt. Gradually mix the dry ingredients into the wet ingredients until just combined.

Step 5:
Fold in the oats, raisins, and nuts (if using) until evenly distributed.

Step 6:
Using a cookie scoop or tablespoon, drop dough onto the prepared baking sheets, spacing them about 2 inches apart.

Step 7:
Bake for 10–12 minutes or until the edges are lightly golden, and the centers appear slightly underbaked (they’ll firm up as they cool).

Step 8:
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.