Preheat oven to 325 degrees then line the bottom of two 9" cake pans with parchment paper. Spray the pans and paper with non-stick cooking spray and set aside.
In a large mixing bowl, whisk the sugar, oil and eggs together until completely blended then set aside.
Add the carrots to the bowl of a food processor fitted with the steel blade and pulse until the carrots are very finely chopped and resemble the texture of wet sand. Then, add them to the sugar, oil and egg mixture, stirring to combine.
Sift the flour, baking soda, salt, and cinnamon on top of the wet ingredients and carefully fold the wet and dry ingredients until completely blended. If you’d like to add nuts or raisins, now is the time to fold them into the batter (our office voted a unanimous ‘no’).
Divide the batter evenly into the two prepared cake pans and bake 45−50 minutes—the cakes will be firm in the center and just beginning to pull away from the sides of the pan.
Remove the cakes from the oven and cool them on a rack for about 10 minutes.
When the cakes have rested but are still quite warm, invert the layers onto a sheet of waxed paper. Remove the pan, peel the parchment paper from the bottom of the cake then replace the pan back over the cake to cover it and seal in the moisture. Leave the cakes covered until they are completely cooled (at least 2 hours).
While the cakes are cooling, get started on the cream cheese frosting. Add the softened butter and cream cheese to a medium-sized mixing bowl and cream together until completely combined and no lumps remain. Then, sift in the powdered sugar, stirring until perfectly smooth.
Add the vanilla and stir once more to combine. If the frosting’s too thick, add a few drops of milk until the consistency’s correct. Cover with plastic wrap and store at room temperature until you are ready to frost the cake.
When the cakes are cool and the frosting has been made, remove the pans to uncover the cakes. Place the first layer on a serving plate and evenly coat the top of the cake with frosting. Place the next layer upside down on top of first layer and press gently but firmly into place. Coat the top and all sides of the cake evenly with the remainder of the frosting.
Refrigerate the cake until ready to serve then slice into big wedges and enjoy!