In a bowl, combine the first five ingredients; beat until smooth. Combine flour, cinnamon, baking soda, orange zest and salt; add to buttermilk mixture and mix well. Stir in carrots, coconut, nuts and pineapple. Pour into three greased and floured 9-in. round baking pans. Bake at 350° for 35-40 minutes or until a toothpick comes out clean. Place pans on wire racks.
In a saucepan, combine the first five glaze ingredients. bring to a boil; cook and stir for 4 minutes. Remove from the heat; add vanilla. Spread over warm cakes. Cool completely before removing from pans.
In a bowl, combine the first five frosting ingredients; beat until fluffy. Beat in sugar. Place one cake glaze side up on a serving plate; spread with 1 cup frosting. Repeat layers. Frost top and sides of cake.