Grate your carrots if they have not been grated yet. Also, preheat your oven to 350 and prep two round cake pans or pans of choice for nonstick.
In a medium bowl, use a whisk to combine together the the flour, baking powder, baking soda, sugar, cinnamon, nutmeg, and salt.
In a mixing bowl, cream together the oil and the sugar until light and fluffy. Then add the milk, eggs and vanilla extract and mix until combined. Add the dry ingredients from the first bowl to mixing bowl and beat until just combined. Lastly, fold in in the grated carrots. Bake the cakes for for 30-35 minutes, or until a toothpick inserted into the center comes out clean. Then allow cakes to cool completely before frosting.
To make the frosting, in a mixing bowl, cream together the combine the softened cream cheese and butter. Then stir in the vanilla extract.
Add half of the powdered sugar and continue to mix. Then stir in the remaining powdered sugar in increments until you reach your desired texture of frosting. You may need more or less than the specified amount of powdered sugar depending on the texture of the frosting that you want. Once your carrot cakes are fully cooled, use a serrated (bread) knife to make the cakes level. Usually this means slicing off the center when the cake may have risen more.
Frost the tops of each of the cakes and then layer the cakes, with the frosted sides up, to put the cake together. You can then add any additional frosting and toppings before serving.