Makes one 9-by-13-inch rectangular or one 8-inch round cake
For the Cake:
4 large eggs
1 cup Hellman’s olive oil mayonnaise
1 cup granulated sugar
1 cup light brown sugar, packed
1 tablespoon pure vanilla extract
2 cups all-purpose flour
2 teaspoons baking soda
2 teaspoons baking powder
1 teaspoon kosher salt
¼ cup grated fresh peeled ginger
2 teaspoons ground cinnamon
2 ½ cups grated carrots (from about 1 pound whole carrots)
¾ cup roughly chopped hazelnuts
For the Frosting:
8 tablespoons (1 stick) unsalted butter, softened
8 ounces cream cheese, softened
3 cups confectioners’ sugar
¼ cup molasses
Make the Cake:
Preheat the oven to 350 degrees F. Grease and flour a 9- by 13-inch pan or an 8-inch springform pan.
In a large bowl, beat together the eggs, mayonnaise, granulated sugar, brown sugar, and vanilla. Mix in the flour, baking soda, baking powder, salt, ginger, and cinnamon. Stir in the carrots. Fold in the hazelnuts and pour the batter into the prepared pan.
Bake for 40 to 50 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let cool in the pan for 10 minutes, then turn out onto a wire rack and cool completely.
Make the Frosting:
In a medium bowl, combine the butter, cream cheese, confectioners’ sugar, and molasses. Beat until the mixture is smooth and creamy, then slather it on the cooled cake.