Preheat oven to 350°F and line a baking sheet with parchment paper.

In a small bowl, whisk together flour, baking soda, cinnamon, nutmeg, and salt.

In a large bowl, cream butter, brown sugar, and granulated sugar until light and fluffy.

Beat in the egg and vanilla.

Stir in grated carrots, oats, and any add-ins like walnuts or raisins.

Add the dry ingredients to the wet and mix until just combined.

Scoop dough onto the prepared baking sheet, spacing a couple inches apart.

Bake for 10–12 minutes or until edges are set and centers look soft.

Let cool on the pan for 5 minutes, then move to a wire rack to cool completely.

Frost with cream cheese icing if you want—store leftovers in the fridge.