Preheat oven to 350°.
Spray two 9" round cake pans with cooking spray and cut parchment circles to place into the bottoms. Or you can bake this cake in a greased 9x13'" pan.
In a mixing bowl, with paddle attachment, mix oil and sugar.
Add the eggs and mix until creamy.
Add the shredded carrots and pineapple. Mix to combine.
In a separate bowl, mix the flour, baking powder, soda, salt, and cinnamon. Add this to the wet ingredients and mix only to combine.
Stir in the nuts.
Bake for 32 - 40 minutes or until a toothpick inserted in the center comes out clean. Cool.
Beat the cream cheese until smooth, add the butter, and beat till it's creamy.
Add the vanilla, salt, and powdered sugar and mix, scraping the sides of the bowl. Beat for about a minute or until it's creamy and fluffy.
Frost cake when cool.
Store this cake in the refrigerator for up to a week.
