Creating Hawaiian Carrot Pineapple Cake involves a few simple steps that anyone can follow:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
2. Mix Dry Ingredients: In a large bowl, whisk together the flour, sugar, baking powder, baking soda, cinnamon, and salt until well combined.
3. Combine Wet Ingredients: In another bowl, mix the vegetable oil, eggs, grated carrots, crushed pineapple, and vanilla extract until smooth.
4. Combine Mixtures: Gradually add the wet mixture to the dry ingredients, stirring until just combined. Be careful not to overmix.
5. Add Nuts: If desired, fold in the chopped walnuts or pecans for an added crunch.
6. Pour Batter: Divide the batter evenly between the prepared cake pans.
7. Bake: Bake in the preheated oven for 35-40 minutes, or until a toothpick inserted in the center comes out clean.
8. Cool the Cakes: Allow the cakes to cool in their pans for 10 minutes before transferring them to wire racks to cool completely.
9. Prepare Frosting: While the cakes cool, prepare the cream cheese frosting. In a bowl, beat the softened cream cheese and butter until smooth. Gradually add the powdered sugar and vanilla extract, mixing until creamy. Add milk if necessary to achieve the desired consistency.
10. Frost the Cake: Once the cakes are completely cooled, place one layer on a serving platter. Spread a generous layer of frosting on top. Place the second layer on top and frost the top and sides of the cake.