Preheat your oven to 350°F (175°C) and grease and line cake pans with parchment paper.

In a large mixing bowl, whisk together the all-purpose flour, baking powder, baking soda, cinnamon, nutmeg, and salt.

In another bowl, mix the granulated sugar, brown sugar, and vegetable oil until smooth. Gradually incorporate the eggs, mixing well.

Gently fold the dry mixture into the wet ingredients until no flour streaks remain.

Fold in the grated carrots, drained crushed pineapple, and optional shredded coconut into the batter.

Divide the batter between cake pans and bake for 30 to 35 minutes until a toothpick comes out clean.

Allow the cakes to cool in the pans for 10 to 15 minutes, then invert onto wire racks.

Beat the cream cheese and unsalted butter together until creamy. Gradually add powdered sugar, vanilla extract, and milk or pineapple juice.

Once cooled, frost the cakes and serve, optionally adding toasted coconut or nuts.