Grate zucchini, squeeze dry.
Whisk flour, baking soda, baking powder, cinnamon, nutmeg, and salt.
Whisk eggs, sugars, oil, and vanilla; stir in zucchini.
Combine wet and dry ingredients; fold in nuts.
Preheat oven to 350°F. Pour into greased 9x5-inch pan; bake 55-65 min.
Cool 10 min in pan, then rack. Dust with sugar; serve with butter, coffee.