Preheat oven to 350°F. Grease a 10-inch Bundt pan.
In a medium bowl, stir together your flour, cinnamon, nutmeg, baking soda, baking powder, and salt; set aside.
In a large mixing bowl, beat the oil, sugar, eggs, and vanilla for about a minute. Pour in the flour mixture and mix on low until just combined. Add in the carrots and nuts (optional). Pour batter into your prepared Bundt pan and bake for 45-60 minutes or until a toothpick inserted in the middle comes out clean.
Place on a cooling rack and let cool completely before removing from pan.
While cake is baking, whip together the frosting ingredients—butter, cream cheese, confectioner’s sugar, vanilla, and orange zest—until smooth and creamy. Refrigerate frosting when not using.
Once cake is cooled and removed from pan, dust lightly with confectioner’s sugar. Slice and serve with cream cheese frosting on the side. Enjoy!