Step 1

For the cookies: Preheat the oven to 350° with oven racks in the upper and lower thirds of the oven. Line 3 baking sheets with parchment paper; set aside.

Step 2

Beat the butter, brown sugar, and granulated sugar in the bowl of a stand mixer fitted with the paddle attachment on medium speed until pale and creamy, about 3 minutes. Add the eggs and vanilla extract. Beat until well combined, stopping to scrape the sides of the bowl, as needed.

Step 3

Whisk together the flour, cinnamon, ground ginger, baking powder, baking soda, and salt in a medium bowl. Gradually add the flour mixture to the butter mixture with the mixer on low. Beat until well combined, about 1 minute. Stir in the carrots and walnuts.

Step 4

Drop spoonfuls (about 2 tablespoons each) of the dough on the prepared baking sheets using a 1 3/4-inch cookie scoop, spacing at least 2-inches apart. Bake two pans at a time, rotating halfway through cooking, until the cookies are lightly browned on the edges, 12 to 14 minutes. Cool the cookies on the pans for 3 minutes. Transfer to a wire rack to cool completely, about 30 minutes. Repeat with the remaining cookies.

Step 5

For the frosting: Beat the cream cheese and butter in the bowl of a stand mixer fitted with a paddle attachment on medium speed until smooth, about 3 minutes. Add the powdered sugar and vanilla with the mixer on low, beating until combined. Increase the speed to medium and beat until fluffy, about 2 minutes.

Step 6

Dollop a spoonful of frosting on the top of each cookie and spread all over the top. Sprinkle with orange jimmy sprinkles or chopped toasted walnuts, if you like.