Preheat oven to 350°. Generously grease 2 round cake pans.
In a mixing bowl, sift flour, baking soda, cinnamon and salt together; set aside.
In a separate bowl, beat eggs. Add oil, buttermilk, sugar and vanilla to egg mixture; mix well.
Add sifted flour mixture, pineapple, carrots, coconut and pecans to egg mixture, mix well.
Pour into cake pans.
Bake 30-40 minutes or until a wooden pick inserted in center of cake comes out clean.
Remove cake from oven. Using a dinner fork, punch 10 - 12 holes in the top of the cakes.
Make buttermilk glaze: In a saucepan, combine sugar, baking soda, buttermilk, butter and corn syrup. Bring to a boil and cook for 5 minutes, stirring occasionally. Remove from heat and stir in vanilla. (Use immediately on warm carrot cakes.)
Slowly pour the buttermilk glaze over the hot cakes (about half the glaze on each cake.)
Cool cakes in pan until glaze is totally absorbed, about 15 minutes.
Place in refrigerator and cool completely.
Prepare cream cheese frosting: Place the butter and cream cheese together in mixing bowl and cream together until fluffy. Using a spatula, scrape down sides of bowl. Add vanilla, powdered sugar, orange juice, and orange peel. Mix on slow speed until smooth.