Preheat the oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan.
In a large mixing bowl, combine the flour, sugar, baking powder, baking soda, salt, cinnamon, and nutmeg.
Add the vegetable oil and eggs to the dry ingredients and mix until well combined.
Fold in the grated carrots, crushed pineapple, and chopped walnuts.
Pour the batter into the prepared baking pan and spread evenly.
Bake in the preheated oven for 45-50 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool completely before frosting.
In a separate mixing bowl, beat the cream cheese and butter until creamy.
Gradually add the powdered sugar and vanilla extract, and continue to beat until smooth and well combined.
Spread the cream cheese frosting evenly over the cooled cake.
Serve and enjoy!