Moist Carrot Zucchini Cake with Cream Cheese Frosting

For the Cream Cheese Frosting:
8 oz cream cheese, softened
1/2 cup unsalted butter, softened
1 cup powdered sugar
1 teaspoon vanilla extract
1/4 cup chopped walnuts for garnish (optional)
Directions:
Preheat your oven to 350°F (175°C). Grease and flour two 8-inch round cake pans.
In a large bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, and nutmeg.
In another bowl, combine the vegetable oil, granulated sugar, and brown sugar. Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the grated carrots, zucchini, and chopped walnuts (if using).