Preheat the Oven: Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans.

Mix Dry Ingredients: In a large bowl, whisk together the flour, sugar, baking powder, baking soda, cinnamon, nutmeg, and salt.

Combine Wet Ingredients: In another bowl, mix the oil and eggs until well combined. Stir in the grated carrots and, if using, crushed pineapple and chopped nuts.

Combine Mixtures: Gradually add the wet mixture to the dry ingredients, stirring until just combined.

Bake: Divide the batter evenly between the prepared cake pans and bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean. Allow the cakes to cool in the pans for 10 minutes before transferring to wire racks to cool completely.

Prepare the Frosting: In a mixing bowl, beat together the cream cheese and butter until smooth. Gradually add the powdered sugar and vanilla extract, beating until light and fluffy.

Assemble the Cake: Once the cakes are completely cool, place one layer on a serving plate. Spread a layer of cream cheese frosting on top, then place the second layer on top and frost the entire cake as desired.

Serve: Slice and serve your delicious carrot cake, enjoying every moist and flavorful bite!