Sift together flour, soda, cinnamon, salt. Set aside. Beat eggs until lemon-colored, then beat in sugars, oil, and buttermilk and vanilla. Stir in flour mixture. Stir in pineapple, carrots, nuts, currants and coconut.
Pour into lightly greased and floured 13 x 9 x 2 inch pan. Bake at 350 degrees F for about 45 minutes or until toothpick comes clean when inserted in center.
Combine all ingredients except vanilla. Bring to boil. Boil 5 to 6 minutes until thick and syrupy. Add vanilla. Poke holes in cake with fork. Pour over cake while still hot. Let cool.
Mix together ingredients and spread on cake.