Combine dry ingredients and set aside.
With a mixer beat the butter and sugar until smooth. Add eggs and beat well. With a spoon stir in vanilla, orange peel, and zucchini. Alternately stir in the dry ingredients and the milk. Add nuts at the last.
Pour into 10-in. tube pan and bake at 350 degrees for about 1 hour. May also be baked in small or medium loaf pans.
Drizzle with sugar glaze or sprinkle with powdered sugar if desired.
Freezes well.