Preheat the oven to 350℉. Spray a 13x9-inch pan with nonstick spray.
MAKE THE CAKE:
In a medium bowl, whisk together the flour, cinnamon, baking powder, baking soda, salt and nutmeg.
In a large bowl, whisk together the oil, sugars and eggs until fully combined. Add in the dry ingredients and whisk until no flour is visible. Stir in the carrots.
Scrape the batter into the prepared pan and smooth the top to make an even surface. Bake until the cake is golden brown and a toothpick inserted into the center comes out clean- 35 to 40 minutes.
Place the cake on a rack to cool completely. When the cake is cool, make the frosting.
MAKE THE FROSTING:
In a large bowl (or bowl of a stand mixer), beat the cream cheese, butter, sour cream, vanilla and salt until smooth. Beat in the sugar, a little at a time until all is smooth. Increase speed to medium-high and beat the frosting until light and fluffy- about 4 minutes. Frost the cake.
Notes
Use freshly grated carrots for the best moisture and flavor.
Let the cake cool completely before frosting so the frosting doesn’t melt.
If you like texture, add ½ cup chopped walnuts or pecans to the batter.
For a slightly tangier frosting, add an extra teaspoon of sour cream.
Store cake covered in the refrigerator for up to 4 days.
Bring slices to room temperature before serving for best flavor.