Preheat the oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.

In a medium bowl, whisk together the flour, baking soda, salt, cinnamon, nutmeg, and ginger. Set aside.

In a large bowl, whisk the granulated sugar and oil until well blended.

Beat in the eggs one at a time, mixing thoroughly after each addition. Stir in the grated carrots and vanilla.

Gradually add the dry ingredients to the wet mixture. Mix on low speed or fold by hand just until combined. Avoid overmixing to keep the cake tender.

Fold in the chopped nuts if using.

Divide the batter evenly between the prepared pans and smooth the tops.

Bake for 30 to 35 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs.

Let the cakes cool in the pans for 10 minutes. Invert onto a wire rack and cool completely before frosting.

To make the frosting, beat the softened cream cheese and butter together until smooth.

Gradually add the powdered sugar until combined. Beat in the vanilla and salt. Continue to beat on medium speed until the frosting is light and fluffy.

Place one cooled layer on a serving plate. Spread about one-third of the frosting over it. Top with the second layer and frost the top and sides. Chill briefly if you want a firmer finish, then serve at room temperature.