For the Carrot Cake:

1. Preheat your oven to 350 degrees Fahrenheit. Grease 3 6-inch round cake pans and line the bottoms with parchment paper.
2. In a medium bowl, whisk together the flour, cinnamon, nutmeg, ginger, allspice, baking powder, baking soda, and salt. Set aside.
3. In a large bowl, cream together the butter, granulated sugar, and light brown sugar until fluffy.
4. Add the eggs and vanilla, mixing until smooth and slightly fluffy.
5. Alternate adding the dry ingredients and the buttermilk to the butter mixture, mixing until combined.
6. Fold in the shredded carrots until evenly dispersed.
7. Divide the batter between the prepared cake pans and bake for 36-41 minutes, or until a toothpick comes out clean. Let cool completely.

For the Cream Cheese Frosting:

1. In a large bowl, whip the butter until pale and fluffy.
2. Add the cream cheese and mix until combined.
3. Gradually add the powdered sugar, mixing until smooth and creamy. Add vanilla extract.
4. Divide the frosting and color as desired with orange and green food coloring.

Assembling the Cake:

1. Level the cake layers.
2. Apply a crumb coat of frosting, then chill for 30 minutes.
3. Apply a final layer of frosting and chill for 20-30 minutes.
4. Decorate the cake with piped carrots and stems using the colored frosting.
5. Add chopped walnuts for extra flair, if desired.
6. Pipe decorative swirls of frosting on top.
7. Serve and enjoy the best carrot cake ever!