In a large bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, and salt.
In separate bowl, beat the oil, sugar, eggs, and vanilla with a hand mixer until smooth. Alternatively can use a stand mixer with the paddle attachment. Then add in the grated carrots.
Add the wet ingredients to the dry ingredients and mix just until combined. Pour the batter into a greased 9x13 inch baking pan.
Bake at 350 degrees F for 32-36 minutes, or until a toothpick inserted into the center comes out clean. Let the cake cool completely before frosting.
Beat together the cream cheese, butter, powdered sugar, milk, and vanilla until smooth and creamy. Spread the frosting over the cooled cake.
Cut into squares and enjoy your delicious creation! This cake is perfect for sharing or just enjoying by yourself (no judgment here).