01 - Preheat oven to 350°F and line two baking sheets with parchment paper.
02 - In a large bowl, beat softened butter, brown sugar, and granulated sugar until light and fluffy, approximately 2-3 minutes.
03 - Beat in eggs one at a time, ensuring full incorporation after each addition. Mix in vanilla extract until combined.
04 - In a separate bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, and nutmeg until well blended.
05 - Gradually add dry ingredients to wet mixture, mixing on low speed just until combined. Avoid overmixing.
06 - Gently fold in grated carrots and chopped nuts until evenly distributed throughout the dough.
07 - Scoop 3-tablespoon mounds of dough onto prepared baking sheets, leaving at least 2 inches of space between each cookie.
08 - Bake for 12-14 minutes until edges are golden brown and centers appear set. Allow cookies to cool on baking sheet for 5 minutes.
09 - Transfer cookies to wire rack and cool completely before frosting, approximately 30 minutes.
10 - Beat cream cheese and butter until smooth and creamy. Gradually incorporate powdered sugar, then add vanilla and salt, beating until fluffy.
11 - Generously spread frosting over each cooled cookie. Garnish with additional chopped nuts if desired.