Preheat oven to 350 F and grease a 9x13 baking pan. In a large bowl sift together the flou, baking powder, baking soda, salt and cinnamon. Add the sugar, corn oil, eggs, and mayonaise stir well. Stir well. Stir in the carrots, nuts, and pineapple. Spread in the greased pan and bake for 30 minutes or till toothpick comes out clean. Cool; frost with cream cheese frosting. Makes 18 3 by 2/14 inch servings.
Cream Cheese Fosting
Whip all ingredients together till fluffy. If the frosting is too thick add a few drops of milk.