Preheat the oven to 350°F (180°C).
To make the cake, grease a 9x13-inch cake pan generously with nonstick cooking spray or butter.
Line the bottom of the pan with parchment paper and grease the parchment.
Make the batter:
Grate the carrots on a box grater directly into a large mixing bowl.
Add the brown sugar, vegetable oil, eggs, pumpkin pie spice, and salt and whisk until fully combined.
Add the flour, baking powder, and baking soda.
Use the whisk to gently stir the batter just until no streaks of flour remain.
Bake:
Pour the batter into the prepared pan.
Bake until a toothpick inserted into the center of the cake comes out clean, 35 to 45 minutes.
Let the cake cool completely in the pan on a wire rack, about 1 hour.
Make the frosting:
While the cake finishes cooling, make the cream cheese frosting.
In a large bowl, use a hand mixer to beat the softened cream cheese and butter on medium-high speed until fully combined and smooth, about 2 minutes.
Add the powdered sugar, salt, and vanilla.
Beat on low speed for 30 seconds, then increase to medium-high and beat until fully combined and creamy, about 3 minutes.
Frost the cake:
Use an offset spatula or the back of a spoon to spread the frosting over the top of the cooled cake.
Slice and serve.
Store the cake, covered, in the refrigerator for up to 5 days.
Servings
Makes one 9x13-inch cake (12 servings)
Nutrition Facts
Nutrition Per Serving (based on 12 servings) - Calories: 480; Total Fat: 27g (Saturated Fat: 9g); Cholesterol: 85mg; Sodium: 370mg; Total Carbohydrates: 57g (Dietary Fiber: 1g, Sugars: 42g); Protein: 5g
*Nutrition information is provided as a general estimate only. Nutrient information is not available for all ingredients, and is based on available nutrient data. Variations may occur based on ingredient brands and preparation methods.