Preheat oven to 350 degrees F and line 2 cookie sheets with parchment paper or silpat mats. In a large bowl, whisk together the flour, oats, baking powder, baking soda, cinnamon, and ground nutmeg.
In a medium bowl, whisk together the melted coconut oil, syrup, brown sugar, egg, and vanilla extract until combined. Scrape down the sides of the bowl and add the carrots, mix again until combined.
Fold the wet ingredients into the dry ingredients Add the raisins and nuts (optional). Mix until all of the ingredients are combined and a cookie dough has formed.
Roll cookie dough out with a mini ice cream scoop and place on cookie sheet, about 1 1/2 inches apart. Gently press down on the cookies with your hand or fingers just a bit to help spread the cookies. Bake for 9-11 minutes, or just until the cookies are slightly golden brown.
In the meantime make the frosting, in a medium bowl beat together the cream cheese, powdered sugar, vanilla extract, butter, and milk until smooth. If the frosting seems too thick, add more milk. If the frosting is too thin, add more powdered sugar.
Once the cookies have baked and cooled, frost and top with more chopped walnuts, cinnamon, and shredded carrots (optional). Enjoy!