Spray 3 (9 inch) round cake pans with cooking spray
Stir together flour, baking soda, salt, and cinnamon – set aside
Beat eggs, sugar, vegetable oil, buttermilk, and vanilla extract at medium speed until smooth
Add flour mixture beating at low speed until blended
Fold in grated carrot, crushed pineapple, flaked coconut, and chopped pecans or walnuts
Pour even amounts of batter into pans
Bake at 350 degrees for 25-30 minutes or until fork comes out clean
For buttermilk glaze: Bring sugar, baking soda, buttermilk, butter, and light corn syrup to a boil in a large pot over medium-high heat
Boil, stirring often, for 4 minutes
Remove from heat and stir in vanilla extract
Drizzle buttermilk glaze evenly over cake layers while still hot
Cool in pans for 15 minutes
Remove from pans and cool completely
For cream cheese frosting: Beat softened butter and cream cheese at medium speed until creamy
Add powdered sugar and vanilla extract, beat until smooth
Spread cream cheese frosting between layers and on top and sides of cake
