Preheat the oven to 350°F. Spray a 13x9-inch pan with nonstick spray.
PREPARE THE CAKE:
In a large bowl, whisk together the flour, sugar, baking soda, cinnamon and salt.
Add the eggs and oil to the dry ingredients. Use an electric mixer to combine the wet and dry ingredients. Stir in the carrots.
Scrape the batter into the prepared pan and spread to cover evenly. Bake for 45 to 50 minute, or until a tester inserted into the middle comes out clean. Let the cake cool before frosting.
PREPARE THE FROSTING:
In a large bowl, use an electric mixer to combine the cream cheese and butter until well combined and smooth. Add the vanilla and 1½ cups of the powdered sugar. Beat until smooth. Add additional powdered sugar, if necessary, until you reach a desired frosting consistency.