Wash zucchini, wipe it off, and cut off the very tip, not the stem. Place the grater onto a sheet of paper towel and use the large grate side of the box grater to grate zucchini all the way down to the stem. Discard the stem.
Spread grated zucchini out a little so it’s no longer in a mound and use another sheet of paper tower to gently pat the excess moisture.
Whisk together zucchini, eggs, oil, vanilla extract, and sugar just until combined.
Add flour, cinnamon, nutmeg, salt, baking soda, and baking powder and gently whisk together just until incorporated and smooth.
Grease a ceramic or glass bread baking dish all over the bottom and up the sides and pour bread batter into it.
Streusel Topping:
In a medium bowl, combine brown sugar, white sugar, cinnamon, and flour. Mix well until all ingredients are incorporated evenly.
Pour in melted butter and carefully fold it in with a large fork. You will want to be careful so you don’t over-mix. Streusel should look like large crumbs and not paste.
Spread streusel topping evenly all over the batter.
Bake at 350° for 55-60 minutes. You can use a thermometer to check if the bread reached internal temperature of 200° in the center. If you don’t have an instant read digital thermometer, you can use your fingers to gently press in the center and see how firm it is or do the toothpick test.
Icing:
Whisk powdered sugar and warmed heavy whipping together and drizzle it over the baked bread.
Video
Notes
Making muffins - to make this bread into muffins, simply divide the batter into the cups of a greased muffin pan, add streusel, and bake for 18-20 minutes. Top them off with the icing.
Can I put undercooked bread back in the oven? Yes, in most cases you can put quick breads right back into the oven to cook more. Make sure the oven is still at the right temperature and bread is hot. Don’t try to bake cooled bread. Place the bread back into the oven for another 10-15 minutes as needed.
Is my bread done? You can use a thermometer to check if the bread reached 200°F in the center. If you don’t have an instant read digital thermometer, you can use your fingers to gently press in the center and see how firm it is or do the toothpick test. I highly recommend getting a thermometer if you cook and bake even a little bit.