Preheat the oven to 350°F. Line two cookie sheets (or baking pans) with parchment paper and set them to the side.
Start by making the cookies. Add the flour, cinnamon, baking powder, baking soda, and salt to a large bowl and stir with a whisk. Set the flour mixture aside.
In a separate large bowl, use an electric hand mixer to cream together the butter and light brown sugar until smooth.
Add the egg and vanilla extract to the butter mixture, and continue blending.
Gradually mix in the dry ingredients until the dough is thick and a little sticky.
Fold in the carrots, then use a cookie scoop to scoop out 1 1/2 tablespoons of dough, roll the dough into a tight, smooth ball, and place the balls about 2 inches apart on the cookie sheets.
Bake the cookies, one sheet at a time for 12-13 minutes or until the edges start to turn golden brown. Allow the cookies to cool on a wire rack.
Make the cream cheese frosting while the cookies are cooling: Blend together the cream cheese and butter until smooth.
Gradually add in the powdered sugar until the frosting is thick and smooth. Spread about 1 tablespoon of frosting on top of each cookie, then sprinkle some crushed walnuts on top.
Store in an airtight container at room temperature for up to 24 hours, then refrigerate for up to 5 days.
Notes
*I used a box grater to finely grate the carrots.Refer to the article above for more tips and tricks.The calories shown are based on the recipe making 24 cookies, with 1 serving being 1 frosted cookie. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information. The information in the nutrition box are calculated through a program and there is room for error. If you need an accurate count, I recommend running the ingredients through your favorite nutrition calculator.**