Recipe
Serves
12 1×
Serves 12 muffinsPrep 20 minCook 20 minTotal 40 min
Ingredients
- Zucchini: Two cups of lightly packed grated zucchini, approximately 240g
- Plain flour: 1¾ cups, approximately 220g
- Unsweetened cocoa powder: ½ cup, approximately 45g
- Baking powder: 1 teaspoon
- Baking soda: 1 teaspoon
- Fine salt: ½ teaspoon
- Large eggs: 2, preferably at room temperature
- Light brown sugar: ¾ cup, packed, approximately 165g
- Granulated sugar: ¼ cup, approximately 50g
- Neutral oil: ½ cup, such as vegetable, sunflower, or avocado oil
- Sour cream or full-fat Greek yoghurt: ⅓ cup, approximately 80g
- Milk: ⅓ cup, approximately 80ml
- Vanilla extract: 2 teaspoons
- Dark or semi-sweet chocolate chips: 1 cup, approximately 170g
- Extra chocolate chips: Optional, for topping
Method
- Preheat the oven to 190°C (375°F) . Line a 12-cup muffin tin with paper cases.
- Grate the zucchini. If it is dripping wet, gently blot or squeeze it once. Do not dry it completely.
- Whisk the eggs, brown sugar, granulated sugar, oil, sour cream, milk, and vanilla in a large bowl.
- Stir the grated zucchini into the wet mixture.
- In a separate bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt.
- Add the dry ingredients to the wet ingredients. Stir just until combined.
- Fold in the chocolate chips.
- Divide the batter between the muffin cases and add extra chocolate chips if desired.
- Bake for 18–22 minutes , until a skewer inserted into the centre shows moist crumbs but no wet batter.
- Cool in the tin for 10 minutes, then transfer to a wire rack.
Chocolate Zucchini Muffins (Moist & Fudgy)
These chocolate zucchini muffins are rich, soft, and brownie-like, with grated zucchini adding moisture without a strong vegetable flavour. Cocoa powder provides deep chocolate flavour, while chocolate chips create melted pockets throughout the crumb.
The batter is simple to prepare in one bowl, and the muffins are ready in about 40 minutes. They are ideal for breakfast, lunch boxes, afternoon snacks, or a straightforward chocolate dessert.
The key is to avoid overmixing and overbaking. The muffins should be removed from the oven when a skewer shows moist crumbs rather than looking completely dry.
Why These Muffins Stay Moist
Zucchini contains a high percentage of water, which helps keep baked goods soft. For the best texture, grate the zucchini on the medium holes of a box grater and gently blot it if it is dripping wet. Do not squeeze it completely dry.
This recipe also uses neutral oil and sour cream. Oil keeps the crumb tender after cooling, while sour cream adds richness and helps create the dense, fudgy texture associated with a brownie.
Using both cocoa powder and chocolate chips gives the muffins two layers of chocolate flavour. The cocoa flavours the batter, while the chips remain soft and slightly melted in the centre.
How to Make Chocolate Zucchini Muffins
1. Prepare the oven and tin
Preheat the oven to 190°C (375°F). Line a standard 12-cup muffin tin with paper cases.
If you are using a dark metal muffin tin, check the muffins near the lower end of the cooking time because dark tins can brown the edges more quickly.
2. Prepare the zucchini
Grate the zucchini using the medium side of a box grater. Measure two cups after grating.
If the zucchini releases a large amount of liquid, place it in a clean kitchen towel and gently blot or squeeze it once. It should remain moist but should not be dripping. Zucchini that is too wet can make the centres gummy, while zucchini that is completely dry will produce less tender muffins.
3. Mix the wet ingredients
In a large mixing bowl, whisk together the eggs, brown sugar, granulated sugar, oil, sour cream, milk, and vanilla extract.
Add the grated zucchini and stir until it is evenly distributed.
4. Mix the dry ingredients
In a separate bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt.
Whisking the dry ingredients first helps distribute the raising agents evenly through the flour and cocoa.
5. Combine the batter
Add the dry ingredients to the bowl of wet ingredients. Stir with a spatula until the flour has just disappeared.
Do not continue mixing once the batter is combined. A few small lumps are acceptable. Overmixing develops gluten and can make the muffins firm rather than soft.
Fold in the chocolate chips, reserving a small handful for the tops if preferred. The finished batter should be thick and scoopable.
6. Fill the muffin tin
Divide the batter evenly between the 12 muffin cases. Fill each case close to the top for a rounded bakery-style finish.
Scatter the reserved chocolate chips over the surface.
7. Bake
Bake for 18–22 minutes, or until the tops are puffed and a skewer inserted into the centre comes out with a few moist crumbs attached.
The skewer should not show wet batter. Avoid baking until it comes out completely clean, as this usually means the muffins have moved beyond a fudgy texture.
8. Cool
Leave the muffins in the tin for 10 minutes. Transfer them to a wire rack and cool further before serving.
The centres will become more stable as the muffins cool, while remaining moist and dense.
Recipe Tips
- Use a kitchen scale if possible. Flour can vary substantially when measured by volume. Too much flour produces dry, heavy muffins.
- Do not squeeze the zucchini completely dry. The retained moisture helps create the soft crumb.
- Use room-temperature eggs. They combine more easily with the oil and dairy ingredients.
- Do not overmix. Stir only until no obvious dry streaks remain.
- Measure cocoa powder accurately. Too much cocoa can make the muffins bitter and dry.
- Use chocolate chips that you enjoy eating. Dark chocolate chips give a less sweet result, while semi-sweet chips create a more balanced flavour.
- Check early. Oven temperatures vary, so begin checking at 18 minutes.
- Cool before storing. Sealing warm muffins can create condensation and a sticky surface.
Variations
Chocolate walnut zucchini muffins
Fold in ½ cup of chopped walnuts with the chocolate chips. The nuts add crunch and reduce the overall sweetness.
Espresso chocolate zucchini muffins
Add 1 teaspoon of instant espresso powder to the dry ingredients. Espresso intensifies the chocolate flavour without making the muffins taste strongly of coffee.
Orange chocolate zucchini muffins
Add the finely grated zest of one orange to the wet ingredients. Orange zest provides a fresh contrast to the dark chocolate.
Dairy-free muffins
Use dairy-free yoghurt or sour cream and plant-based milk. Check that the chocolate chips are also dairy-free.
Mini muffins
Use a mini muffin tin and reduce the baking time to approximately 10–14 minutes. Check with a skewer, as mini muffins can overbake quickly.
Storage
Store cooled muffins in an airtight container at room temperature for up to three days. Place a sheet of kitchen paper underneath and above the muffins to help absorb excess moisture.
For longer storage, freeze the muffins in a sealed freezer bag for up to three months. Defrost at room temperature or warm individual muffins in the microwave for 15–20 seconds.
FAQ
Should zucchini be peeled before grating?
No. The skin is thin, softens during baking, and adds colour and nutrients. Wash and dry the zucchini before grating.
Why are my chocolate zucchini muffins gummy?
The zucchini may have released too much water, or the muffins may have been removed before the centres were fully baked. Gently blot very wet zucchini and bake until a skewer shows moist crumbs rather than liquid batter.
Can I use frozen zucchini?
Yes. Thaw it completely and squeeze out excess water before measuring. Frozen zucchini generally releases more liquid than fresh zucchini.
Can I replace the oil with melted butter?
Yes. Use ½ cup of melted unsalted butter. The flavour will be richer, but the muffins may become slightly firmer once chilled.
Can I make the batter ahead of time?
It is best to bake the batter immediately after mixing because the baking soda and baking powder begin working as soon as they meet the wet ingredients. You can prepare the dry and wet ingredients separately in advance, then combine them just before baking.
How do I know when the muffins are done?
Insert a skewer into the centre of one muffin. It should come out with a few moist crumbs but no wet batter. The tops should look set, and the centres should spring back lightly when pressed.
