Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.

Shred freshly peeled carrots using a box grater or food processor until finely grated, then press to remove excess moisture.

In a medium-sized mixing bowl, whisk together all-purpose flour, ground cinnamon, nutmeg, ginger, allspice, baking powder, baking soda, and sea salt.

In a large bowl, cream the unsalted butter and light brown sugar together using a mixer for about 2-3 minutes.

Add egg yolks and vanilla to the creamed mixture, and mix for an additional 1-2 minutes.

Gently fold in the prepared carrots until evenly distributed.

Gradually add the dry ingredients to the wet mixture and combine gently until just incorporated.

Drop about 2 tablespoons of dough onto the prepared baking sheets, leaving space between each mound.

Bake for 11-13 minutes, rotating the sheets halfway through for even baking.

Allow the cookies to cool on the baking sheets for about 5 minutes before transferring to a wire rack.

In a mixing bowl, whip the softened butter until light and fluffy, then add cream cheese and sift in powdered sugar, mixing until fluffy.

Frost each cookie with cream cheese frosting and sprinkle chopped walnuts on top if desired.