Preheat the oven to 350°.
Grease, flour and line cake pans with parchment paper.
Drain the crushed pineapple.
Peel and grate the carrots.
Beat eggs until light yellow.
Add the sugars, oil and vanilla.
Sift the dry ingredients together.
Pour 1/2 cup of dry ingredients into the batter and then alternate with the buttermilk. End with the buttermilk.
Add carrots, coconut and pineapple.
Mix on low speed until everything is well incorporated.
Pour equal amounts of batter into prepared pans.
Bake for 35 minutes.
Cool for 10 minutes.
Use an offset spatula to loosen the cake from the pan and turn them over onto the cooling rack.
Peel off parchment paper and cool completely.
Frost with cream cheese frosting and decorate with walnuts.