01 - Preheat oven to 350°F and line two baking sheets with parchment paper.
02 - Beat softened butter, brown sugar, and granulated sugar in a large bowl until light and fluffy, approximately 3-4 minutes.
03 - Add eggs one at a time, mixing well after each addition. Stir in vanilla extract until fully incorporated.
04 - Whisk together flour, baking powder, baking soda, salt, cinnamon, and nutmeg in a separate bowl.
05 - Gradually add dry ingredients to wet mixture, mixing just until combined. Avoid overmixing.
06 - Gently fold in grated carrots and chopped nuts until evenly distributed throughout the dough.
07 - Portion dough using a 3-tablespoon scoop onto prepared baking sheets, leaving 2 inches of space between each cookie.
08 - Bake for 12-14 minutes until edges turn golden brown and centers appear set. Cool on baking sheet for 5 minutes before transferring to wire rack.
09 - Beat softened cream cheese and butter until smooth. Gradually incorporate powdered sugar, vanilla, and salt, continuing to beat until fluffy and well-combined.
10 - Generously spread frosting over completely cooled cookies. Garnish with additional chopped nuts if desired.