Ingredients

For the Cake:

• Nonstick cooking spray, for greasing
• 1 cup olive oil
• 1 cup (200g) granulated sugar
• 1 cup packed (213g) light brown sugar
• 1 tablespoon finely grated orange zest
• 1 teaspoon vanilla extract 
• 4 large eggs
• 2 cups (270g) all-purpose flour
• 2 teaspoons ground cinnamon
• 1½ teaspoons kosher salt 
• 1 teaspoon baking powder 
• 1 teaspoon baking soda
• 1 pound carrots, coarsely grated
• 8 ounces (1 medium) sweet potato, coarsely grated

For the Cream Cheese Frosting:

• 8 ounces cream cheese, at room temperature
• 8 ounces (2 sticks) unsalted butter, at room temperature 
• 2½ cups confectioners’ sugar
• 1 teaspoon vanilla extract 
• ½ teaspoon kosher salt

Directions

Make the carrot cake: Preheat the oven to 350°F. Grease a 9 × 13-inch baking dish with nonstick cooking spray.

In a large bowl, whisk together the olive oil, granulated sugar, brown sugar, orange zest, vanilla, and eggs until smooth. Add the flour, cinnamon, salt, baking powder, and baking soda. Gently stir together the dry ingredients piled above the wet ingredients a few times before folding together into a smooth batter. Fold in the carrots and sweet potato until incorporated. Pour into the prepared baking dish and spread in an even layer.

Bake the cake for 40 to 50 minutes,  until golden brown and it reaches an internal temperature of 190°F. (Timing is going to depend on the moisture content of your carrots and sweet potatoes, so while on average it takes me 45 minutes, occasionally the proper internal temperature is reached after 40 minutes, so that is when I start checking.) Let cool completely in the dish.

Meanwhile, make the frosting: In the bowl of a stand mixer fitted with the whisk attachment, whip together the cream cheese, butter, confectioners’ sugar, vanilla, and salt until light and fluffy.

Spread the frosting over the cooled cake, then slice and serve. Store the leftovers in an airtight container in the refrigerator for up to 5 days.