Preheat oven to 350F. Butter two 9-inch cake pans with 1 ½-inch high sides. Using electric mixer, beat sugar and butter in large bowl until light. Add eggs one at a time, beating well after each addition. Beat in orange peel, lemon peel and vanilla. Mix flour, baking powder, baking soda and salt in small bowl. Mix dry ingredients into butter mixture alternately with sour cream in two additions each. Divide batter between prepared cake pans. Bake until tester inserted into centers comes out clean, about 25 minutes. Cool cakes in pans on racks for 20 minutes. Run knife around pan sides to loosen cakes. Turn out cakes on racks; cool completely.

For Glaze: Bring all ingredients to boil in heavy medium saucepan, stirring to dissolve sugar. Boil until reduced to 2/3 cup, about 5 minutes. Cool.

For Frosting: Beat cream cheese and sugar in large bowl until light. Beat in cream of coconut. Using serrated knife, cut each cake horizontally in half. Place one cake layer on patter, cut side up. Brush with ¼ of glaze. Spread ½-cup frosting over cake. Top with second cake layer, cut side up. Brush ¼ of glaze over. Spread ½ cup of frosting over second layer. Top with third cake layer, cut side up. Brush with ¼ of glaze. Spread ½ cup frosting over. Top with fourth layer, cut side down. Brush with remaining glaze. Spread remaining frosting over top and side of cake. Press coconut onto sides of cake. Can be made one day ahead. Cover with cake dome and chill. Let cake stand two hours at room temperature before serving.