Beat eggs, oil, sugar, orange juice, and zest till smooth. Stir in zucchini and vanilla, then dry ingredients. Pour into a large greased and floured Bundt pan. bake at 325 for about 50 minutes or till toothpick comes out clean. Let sit in pan 5-10 minutes, then remove to cooling rack. Cool and frost with orange cream cheese frosting.
For the frosting - Beat butter and cream cheese till smooth. Add powdered sugar, salt, zest, and enough orange juice to make a spreadable consistency.