Zucchini Brownies
A whole zucchini in the batter, and nobody notices it: instead, they stay moist for three days.
- Preparation
- 20 min
- Cook/bake time
- 40 min
- Total
- 1 hr
- Difficulty
- Easy
- Calories
- 204 kcal
- Servings
- 16 pieces
- Prep
- 20 min
- Cooking & baking
- 40 min
Moist chocolate brownies with 250 g zucchini in the batter. You cannot taste or see it, it just provides the water that keeps the crumb moist for days. One wooden spoon, one bowl, no mixer, 204 kcal per piece. The most important step is the one you skip: the zucchini is not squeezed dry.
Why this works
Zucchini consists of about 95 percent water, and exactly this water is the ingredient here, not the vegetable. That is why, unlike for zucchini fritters, it is expressly not squeezed dry: what ends up wrung out in the sink will later be missing in the crumb. The shreds only release their water in the oven, where it is bound in a sugar and starch mixture and stays inside. This is the reason why these brownies are better on the second day than on the first, whereas classic brownies dry out from day one. You cannot taste any of it. Zucchini contains hardly any sugar, no significant acid and almost no volatile flavor compounds, so it simply has nothing to compete with 50 g cocoa. It only remains visible if you grate it too coarsely; on the fine side of the grater, the cell walls break down completely during baking. The half teaspoon of baking soda helps with this: it slightly raises the pH value of the batter, which colors the cocoa darker and accelerates browning.
Step-by-step instructions
- 1
Finely grate the zucchini and do nothing with it
Wash the zucchini, cut off the ends and grate it on the fine side of the grater. Do not peel it as long as the skin is thin and smooth, as it breaks down during baking. And now for the most important step of the recipe, namely the one you skip: the shreds are not squeezed, not salted, not drained. The water in them replaces the milk that is missing in this batter.
- 2
Mix the dry ingredients
Preheat the oven to 180 °C top and bottom heat and line a square baking pan of about 20 by 20 cm with parchment paper that overhangs on two sides. Mix the flour, baking cocoa, baking powder, baking soda and salt in a bowl and stir everything thoroughly before adding anything wet. Otherwise, the cocoa will clump and cannot be dissolved later in such a thick batter.
- 3
Mix the wet ingredients
In a second bowl, stir the brown sugar with the oil, eggs and vanilla extract until the mixture is even. A spoon is enough, nothing needs to be beaten until frothy here. Then fold in the grated zucchini. The mixture will now seem unusually wet, and that is exactly right.
- 4
Combine, but briefly
Add the wet mixture to the dry ingredients and stir only until no more flour is visible. The batter is tough and heavy. Resist the reflex to pour in milk, because the zucchini only releases its water in the oven. Finally, fold in the chopped chocolate and smooth the batter in the pan.
- 5
Bake and let cool completely
Bake for 35 to 40 minutes. The toothpick test is different here than with a classic brownie: moist crumbs on the toothpick are right, liquid batter means five minutes more. Let the brownies cool completely in the pan before lifting them out by the paper. Cut warm, they will tear, because the water from the zucchini only allows the crumb to set as it cools.
Our best tips
- Use the fine side of the grater, not the coarse one. Coarse shreds survive baking as visible green threads, and then the whole idea of nobody noticing the zucchini is ruined.
- Bake a day ahead. The water from the zucchini distributes itself in the crumb overnight; on the second day, the brownies are moister than fresh from the oven. This is true for hardly any other baked good.
- A large zucchini from a neighbor yields a good two baking pans. The batter can easily be doubled, and the second pan goes straight into the freezer, whole, not in cubes.
Tasty variations
Zucchini Muffins
Divide the same batter among 12 muffin cups and bake for 20 to 22 minutes. Because of the smaller shape, they dry out sooner than the baking pan, so it is better to take them out two minutes early.
Gluten-free
Replace the 180 g flour with 160 g gluten-free flour blend and 20 g ground almonds. The batter then needs 10 minutes of rest before baking so that the starches absorb the zucchini water.
Vegan
Instead of the eggs, mix 2 tablespoons of ground flaxseed with 6 tablespoons of water and let swell for 10 minutes. The zucchini brings enough moisture anyway, the crumb just becomes a little denser as a result.
As a Chocolate Zucchini Cake
Pour the same batter into a loaf pan (30 cm) and bake for 50 to 55 minutes at 170 °C. Taller means longer and lower: at 180 °C the crust would be dark before the center is done.
Nutrition facts
| Calories | 204 kcal |
|---|---|
| Protein | 3 g |
| Carbohydrates | 24 g |
| – of which sugar | 14 g |
| Fat | 10 g |
| Fiber | 2 g |
Where the 204 kcal come from
per serving
Calculated from the ingredients – how we do it
We add up reference values for every ingredient and divide by the number of servings. These assumptions are baked in:
- Reference values per 100 g – for the raw ingredient, exactly as listed.
- Tinned goods count at drained weight, bone-in meat at purchase weight: you eat about 70 per cent of a chicken thigh and leave the rest.
- Water evaporates as you cook. The energy stays in the pot, the weight does not – so the figure is per serving, not per 100 g of finished dish.
- Anything listed without a quantity – “salt and pepper” – is not counted.
A guide value, not a lab measurement: no two onions weigh the same, and fat content varies from pack to pack.
What can go wrong
The points where this recipe most often goes sideways – and what to do about it.
- The batter is so tough that I want to pour in milk
- Do not do it. A zucchini brownie batter is significantly firmer than a sponge batter, because the 250 g of shreds only release their water in the heat of the oven. Until then, it sits in the cells. Anyone who pours in liquid now brings water into the same batter twice and gets a soggy center that never bakes through.
- Green threads are visible in the slice
- Grated too coarsely. The coarse side of the grater creates strips whose cell walls survive baking; on the fine side they break down. With a very large zucchini with a firm, dark skin, both come together. You peel those beforehand, but with the usual medium-sized ones this is unnecessary.
- The center remains soggy, the edge is done
- The pan was too small, making the layer too thick. For 20 by 20 cm, 35 to 40 minutes is right. With a smaller pan, cover the brownies loosely with aluminum foil after 30 minutes and give them ten minutes more so that the center cooks through without the edge getting dark.
- The brownies turned out dry
- The zucchini was squeezed dry or salted and drained, a step from the fritter recipe that does exactly the opposite here. This batter contains no milk and no cream; the water from the zucchini is the entire liquid. Without it, about 240 g are missing, and you can taste that from the first forkful.
Frequently asked questions
Can you taste the zucchini in the brownies?
No. Zucchini contains hardly any sugar, no significant acid and almost no volatile flavor compounds, so it has nothing to counter 50 g cocoa and 120 g chocolate in terms of taste. It only becomes visible if you grate it too coarsely.
Do I have to squeeze the zucchini dry?
No, and that is the most common mistake with this recipe. The batter contains neither milk nor cream; the water from the shreds is the entire liquid. Squeezed dry, about 240 g are missing, and the brownies become dry instead of moist.
Do I have to peel the zucchini?
Not with the usual medium-sized zucchini, as the thin skin breaks down during baking. Only very large specimens with firm, dark skin and pronounced seeds should be peeled and seeded beforehand, because both remain visible.
How much zucchini is 250 grams?
About one medium-sized zucchini of around 20 cm, grated a good two cups. Being more precise than 'one zucchini' is actually worth it here, because the water in it is the liquid of the recipe. Adding 100 g too much makes the center soggy.
How long do zucchini brownies keep?
Airtight at room temperature for five days, and the first three they get better instead of worse. The water from the zucchini distributes itself in the crumb overnight. Frozen they keep for three months, ideally whole and not in cubes.
Do I really need baking powder and baking soda?
Both together, yes. The baking powder leavens, the baking soda does something else: it slightly raises the pH value, colors the cocoa darker and accelerates browning. Baking soda alone is not enough, because there is too little acid in the batter to fully activate it.
How many calories do zucchini brownies have?
Around 204 kcal per piece for 16 pieces from a 20 by 20 cm pan. For comparison, classic brownies with butter and chocolate are around 315 kcal per piece. The difference is the zucchini, which contributes liquid without significant energy.
Comments & ratings(0)
Sign in to rate and comment on this recipe.
You might also like
DessertsPeach Crumble with Oat Streusel
One kilo of peaches, one baking dish, forty minutes, and streusel that still crunches the next day.
Leftover CookingLeftover Egg Whites 3 Ways
Meringue, financiers or an omelet, depending on how many egg whites are in the jar.
Cakes & PastriesMoist Lemon Cake
Pound cake with lemon zest, syrup soak, and white glaze, moist for days.