Ingredients
Equipment
Method
Prep and heat
- Preheat the oven to 350°F and grease a 9x5 loaf pan, so the loaf bakes evenly with quick release from the pan.
Make the cinnamon swirl
- Mix 3 tablespoons brown sugar and 1.5 teaspoons cinnamon together in a small bowl, until the mixture looks evenly speckled and set aside for later.
Mix the dry ingredients
- Whisk all-purpose flour, baking soda, baking powder, salt, 2 teaspoons cinnamon, and nutmeg together until the dry mixture is uniform in color.
Mix the wet ingredients
- Beat brown sugar, eggs, vegetable oil, sour cream, and vanilla extract until smooth and glossy.
Add fruit and zucchini
- Stir grated zucchini (squeezed dry) and finely diced apple into the wet mixture, distributing the pieces through the batter.
Combine batter
- Fold the dry ingredients into the wet ingredients until just combined, stopping when no dry streaks remain for a tender crumb.
Layer and swirl
- Pour half the batter into the loaf pan and sprinkle the cinnamon swirl mixture on top in an even layer.
Swirl and bake
- Add the remaining batter, then swirl with a knife to create cinnamon ribbons through the loaf.
Bake, cool, and finish
- Bake at 350°F for 55–65 minutes, until a toothpick comes out clean with only a few moist crumbs at most.
Cool and drizzle
- Cool for 15 minutes in the pan, then drizzle with caramel sauce if desired before slicing.
Notes
Pro tip: squeeze the grated zucchini well so the loaf bakes up golden instead of soggy. Store covered at room temperature up to 3 days or refrigerated up to 5 days; freeze slices up to 2 months. For a lower-sugar swap, use part of the brown sugar with an equal amount of your preferred baking sweetener and reduce caramel drizzle.