01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, and nutmeg. Set aside.
03 - In a large bowl, beat the softened butter, brown sugar, and granulated sugar until light and creamy.
04 - Add the egg and vanilla extract, beating until well combined.
05 - Gradually add the dry ingredients to the wet ingredients, mixing just until incorporated.
06 - Stir in the oats, grated carrots, nuts, and raisins (if using) until evenly distributed.
07 - Drop heaping tablespoons of dough onto the prepared baking sheets, spacing about 2 inches apart.
08 - Bake for 11–13 minutes, or until edges are golden and centers are still slightly soft.
09 - Let cookies cool on the baking sheets for 5 minutes before transferring to a wire rack to cool completely.