Ingredients
Equipment
Method
Prepare and preheat
- Preheat your oven to 350°F and grease a 9x5 loaf pan so the batter releases cleanly after baking.
Make the cinnamon swirl
- Mix granulated sugar, cinnamon, and melted butter until it forms a loose paste, then set aside for swirling.
Mix the dry ingredients
- Whisk all-purpose flour, baking soda, baking powder, salt, and cinnamon until evenly combined with no visible streaks of baking soda or powder.
Mix the wet ingredients
- Beat granulated sugar, eggs, vegetable oil, Greek yogurt, and vanilla extract until smooth, then stir in the grated squeezed zucchini.
Combine batter
- Fold the dry ingredients into the wet mixture just until combined, stopping as soon as you no longer see dry flour.
Layer and swirl
- Pour half the batter into the prepared loaf pan and drizzle half the cinnamon swirl over the surface, then drag a knife through in a figure-eight pattern to start the ribbon.
Finish swirling and bake
- Add the remaining batter, drizzle the remaining cinnamon swirl, and swirl again with a figure-eight motion to create a continuous cinnamon spiral.
Bake and cool
- Bake for 55–65 minutes at 350°F until a toothpick inserted in the center comes out clean, with the top springing back slightly.
- Cool the loaf for 20 minutes before slicing so the cinnamon ribbon sets and the center finishes steaming through.
Notes
For the best swirl, squeeze the grated zucchini very dry so it doesn’t water down the cinnamon ribbon. Store sliced bread covered at room temperature for up to 2 days or refrigerated for up to 5 days; freeze whole or sliced for up to 3 months. To keep it lower fat, you can swap part or all of the vegetable oil for plain Greek yogurt (reduce oil to 1/4 cup and increase yogurt to 1/2 cup), but expect a slightly softer crumb.