Place flour mixture, baking soda, cinnamon and salt in a bowl and mix with a wire whisk.
Beat sugar, eggs buttermilk, oil and vanilla into the flour mixture. Fold in carrots, pineapple, coconut and walnuts to the batter.
Here are the directions for the layer cake. Grease and flour a 10" springform pan. Add batter to the pan. Place on a cookie sheet in a preheated 250 degree F. oven for about 1 hour and 15 minutes, or until golden brown and a toothpick inserted comes out clean. Let cool completely on a wire rack before removing from pan. Then slice cake horizontally to make 2 layers, rather than baking two thinner layers. (Note* I made 24 cupcakes, using about 1/4 cup batter for each cupcake liner. I baked them at the same, lower temperature, of 250 F. for 60 minutes.)