Preheat the Oven:
Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans, or line them with parchment paper.

Prepare the Cake Batter:
In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, and salt. Set aside.
In a large mixing bowl, beat the eggs, granulated sugar, and brown sugar until light and fluffy. Add the oil and vanilla extract, and mix until fully combined.
Gradually add the dry ingredients to the wet ingredients, mixing just until combined.
Stir in the grated carrots and chopped walnuts, ensuring they are evenly distributed in the batter.

Bake the Cake:
Divide the batter evenly between the prepared cake pans. Smooth the tops with a spatula.
Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean. Let the cakes cool in the pans for 10 minutes before transferring them to a wire rack to cool completely.

Make the Cream Cheese Frosting:
In a large mixing bowl, beat the softened cream cheese and butter together until smooth and creamy. Gradually add the powdered sugar, 1 cup at a time, and continue to beat until smooth. Add the vanilla extract and heavy cream (if using) for a creamier texture. Beat until fluffy and well combined.

Assemble the Cake:
Once the cakes are completely cool, place one cake layer on a serving plate or cake stand. Spread a generous layer of cream cheese frosting on top. Place the second cake layer on top and frost the top and sides of the entire cake.
Garnish with additional chopped walnuts on top or around the sides for extra crunch and decoration.

Serve:
Slice and enjoy this delicious, moist carrot walnut cake! It’s perfect for birthdays, special occasions, or as an everyday treat.