Preheat the oven to 350°F (175°C). Grease and flour a 9×13-inch baking pan.
In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, salt, ground cinnamon, ground nutmeg, and ground ginger until well combined.
In a large bowl, beat the granulated sugar, light brown sugar, and vegetable oil until smooth.
Add the eggs one at a time to the sugar and oil mixture, beating well after each addition.
Stir in the vanilla extract.
Gradually add the dry ingredients to the wet ingredients, mixing just until combined.
Fold in the grated carrots, shredded coconut, and chopped walnuts until evenly distributed.
Pour the batter into the prepared baking pan and spread it evenly.
Bake for 35 to 40 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cake from the oven and let it cool completely in the pan on a wire rack.
While the cake cools, prepare the cream cheese frosting: In a medium bowl, beat the softened cream cheese and unsalted butter until smooth and creamy.
Gradually add the powdered sugar, beating until the frosting is light and fluffy.
Mix in the vanilla extract.
Once the cake is completely cooled, spread the cream cheese frosting evenly over the top.
Sprinkle the toasted shredded coconut over the frosting for garnish.
Cut into 12 pieces and serve.