The short version: Grate two cups of zucchini, drain it in a sieve while you mix, and fold it into a cocoa batter with chopped dark chocolate instead of chips. Bake at 350°F for 55–65 minutes. The zucchini disappears completely and leaves behind a crumb that stays moist for four days.
Every August, someone in Fredericksburg leaves a paper sack of zucchini on a neighbor's porch and walks away without knocking. It's a Hill Country tradition of sorts. We've been on both ends of that sack, and after a few summers of experimenting in the chocolate kitchen, this is where we landed: zucchini bread that tastes like a fudgy chocolate cake, with no hint of the garden anywhere in it.
Zucchini is doing one job here, and it isn't flavor. It's roughly 95% water, and grated fine it releases that moisture slowly into the crumb as the loaf bakes. What you get is the texture of a cake that's been sitting under a dome all day — tender, close-grained, still soft on day three. Cocoa powder covers the color, dark chocolate covers the rest.
Why chopped bar chocolate, not chips
Chocolate chips are engineered to hold their shape. They carry stabilizers and less cocoa butter for exactly that reason, so they survive the oven as discrete little pellets. That's useful in a cookie. In a quick bread it means the chocolate stays a passenger.
Chop a bar instead — anything from 56% to 70% — and you get a range of pieces from dust to thumbnail. The dust melts into the batter and deepens the whole loaf. The larger shards soften into seams that stay glossy when you cut a warm slice. Our 56% Colombia bar sits in the sweet spot: bright red-fruit notes up front, roasted and low at the finish, sweet enough that you don't need to touch the sugar. A 70% will give you a drier, more bitter loaf that's worth trying if you like your chocolate serious.
For the cocoa powder, Dutch-process is our preference here. It's alkalized, so it's darker, smoother, and less acidic — which matters because this batter leans on baking soda, and natural cocoa's acidity can tip the rise. If natural cocoa is what's in the pantry, use it; the loaf will be a shade lighter and a touch fruitier.
Ingredients
Makes one 9×5-inch loaf, about 10 slices.
Dry
- 1½ cups (190g) all-purpose flour
- ½ cup (45g) Dutch-process cocoa powder
- 1 teaspoon baking soda
- ½ teaspoon baking powder
- ¾ teaspoon fine sea salt
- 1 teaspoon ground cinnamon (optional, and it does quietly good work)
Wet
- 2 large eggs, at room temperature
- ½ cup (100g) granulated sugar
- ½ cup (110g) packed light brown sugar
- ½ cup (120ml) neutral oil — canola, grapeseed, or light olive
- ¼ cup (60g) sour cream or whole-milk yogurt
- 2 teaspoons vanilla extract
The rest
- 2 packed cups (about 250g) grated zucchini, from roughly 1 medium-large squash — you'll drain this down to about 1½ cups
- 1 cup (170g) dark chocolate, 56–70%, roughly chopped, plus a small handful for the top
Method
- Heat the oven to 350°F (175°C). Grease a 9×5-inch loaf pan and line it with a parchment sling so you can lift the loaf out later.
- Grate and drain the zucchini. Use the large holes of a box grater — no need to peel it, the skin softens completely and adds nothing but flecks. Pile the shreds in a sieve set over a bowl and leave them there while you mix everything else, about ten minutes. Press gently at the end. You want it damp, not wrung out.
- Whisk the dry ingredients together in a medium bowl: flour, cocoa, baking soda, baking powder, salt, cinnamon. Break up any cocoa lumps with your fingers.
- Whisk the wet ingredients in a large bowl: eggs and both sugars first, until the mixture pales slightly and thickens, about a minute. Then the oil, sour cream, and vanilla.
- Combine. Add the dry to the wet and fold with a spatula until just a few streaks of flour remain. Stop early. Every extra stroke builds gluten, and gluten is what turns a quick bread rubbery.
- Fold in the zucchini and chocolate in two or three passes, until the shreds are evenly distributed. The batter will be thick and will loosen as it bakes.
- Bake 55–65 minutes. Scrape into the pan, scatter the reserved chocolate over the top, and bake until the loaf domes and cracks and a skewer inserted at the center comes out with moist crumbs — not wet batter, and not perfectly clean. Melted chocolate on the skewer is not doneness; look at the crumb clinging beside it.
- Cool at least an hour. Ten minutes in the pan, then lift it out onto a rack. A warm slice is a soft, messy pleasure, but the crumb won't set properly until it's cooled through.
Four things that decide whether this works
- Drain, don't wring. Squeezing the zucchini bone-dry in a towel takes out the moisture you're baking for and gives you a dense loaf. A sieve and gravity is the whole technique.
- Measure the zucchini packed. Loosely piled shreds can be half the weight of packed ones. If you have a scale, 250g grated is the number.
- Underbake before you overbake. Set a timer for 50 minutes and start checking. This loaf goes from moist to dry faster than a banana bread does, because there's cocoa in it soaking up water.
- Room-temperature eggs. Cold eggs seize the batter and you'll fight it. Ten minutes in warm water solves it.
Variations worth making
- Muffins: same batter, lined tin, 350°F for 20–24 minutes. Makes 12.
- Pecans: a cup of toasted Texas pecans, folded in with the chocolate. Toast them first — seven minutes at 350°F while the oven comes up.
- Espresso: a teaspoon of instant espresso powder whisked into the dry ingredients. You won't taste coffee; you'll taste more chocolate.
- Sea salt finish: a light scatter of flaky salt over the chocolate on top before it goes in.
Storing it
Wrapped well at room temperature, it holds for four days and is arguably better on day two, once the crumb has settled. Refrigeration dries it out — skip it. For longer, wrap the cooled loaf in plastic and then foil and freeze up to three months; thaw overnight on the counter. Slices freeze individually too, which is the honest solution to a counter full of squash.
What to drink with it
A thick cup of our gourmet drinking chocolate alongside a warm slice is almost too much of a good thing, and we recommend it anyway. In the evening, a glass of Moscato d'Asti works better than you'd expect — the low fizz and stone-fruit sweetness cut straight through the cocoa. If you're in Fredericksburg, come by the shop and we'll walk you through pairing a slice with something from the wine side.
Questions we get about zucchini bread
Do you have to peel the zucchini? No. The skin is thin and softens completely in the oven. In a chocolate loaf you won't even see the flecks.
Do you squeeze the water out of zucchini for bread? Drain it, don't squeeze it. Ten minutes in a sieve with a gentle press at the end removes the excess liquid that would make the loaf gummy, while keeping the moisture that makes it tender. Wringing it dry in a towel goes too far.
Can you taste the zucchini? Not in this recipe. Zucchini has almost no flavor of its own, and cocoa plus chopped dark chocolate covers what little there is. It reads as chocolate cake.
Why is my zucchini bread gummy or wet in the middle? Usually undrained zucchini, an overmixed batter, or pulling it out early because melted chocolate on the skewer looked like raw batter. Check the crumbs clinging to the skewer, not the chocolate streaks.
Can I use frozen grated zucchini? Yes. Thaw it fully, then drain — frozen zucchini sheds far more water than fresh, so let it sit in the sieve longer and expect closer to 1¼ cups after draining.
Can I cut the sugar? You can drop the granulated sugar to ¼ cup and the loaf still works, especially with a 56% chocolate. Below that the crumb turns dry — sugar is holding water here, not just sweetening.
Cocoa powder or melted chocolate in the batter? Cocoa powder for structure and color, chopped chocolate for the melting seams. Both, in other words, which is why this loaf tastes deeper than most.