In a mixer, cream butter and sugar. Add in eggs, one at a time and continue to beat until incorporated and creamy. Add salt and orange rind and mix well.
Dissolve the baking soda in the buttermilk and add to the creamed mixture, alternating with flour. Mix well.
Bake for 60 minutes, or until an inserted toothpick comes out clean.
Mix glaze ingredients and pour over warm cake.