Dark Chocolate Rhubarb Brownies
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Chocolate rhubarb brownies are a rich and decadent treat that has the best slightly tart flavor of rhubarb which cuts through the sweetness like magic. They’re moist, fudgy, and sweet with chocolate chips and walnuts and just the right amount of rhubarb flavor. You’ll love them!
These are the brownies I make every spring, and they’re a little different in the best way. The standout is the rhubarb—it softens as it bakes, creating little pockets of moisture that make the brownies extra tender.
I love the texture it brings. It reminds me a bit of what carrots do in carrot cake—subtle, but it changes the whole feel of the brownie. The rhubarb weaves through each bite, adding a gentle tang that balances the sweetness without taking over.
They’re rich, soft, and just a little unexpected. Once they’re out of the pan, they tend to go quickly.
How to make rhubarb brownies
Most brownie recipes are pretty straightforward, and this one is no exception. In fact, it’s one of the easier ones. Here’s what you’re going to do:
- Whisk the wet ingredients in a bowl.
- Now whisk the dry ingredients in another bowl.
- Then combine them together and stir in the rhubarb, chocolate chips, and walnuts.
- Scrape the batter into a parchment paper-lined baking dish then put the brownies into your oven.
The hardest part of making this recipe is waiting for the brownies to cool before you cut into them!
How to make extra-thick brownies
Sometimes nothing but extra-thick brownies will do. If that’s what you’re craving, double the recipe. Here are the measurements:
1 ½ cups sugar, ¾ cups vegetable oil, 3 eggs, 1 ½ teaspoons vanilla, ¾ cup flour, 1/3 cup + 3 tablespoons cocoa powder, ¾ teaspoon baking powder, ¾ teaspoon salt, 1 ½ cups rhubarb, ¾ cup chocolate chips, ¾ cups chopped walnuts.
For extra-thick rhubarb brownies, bake for an additional 5 minutes.
Can I make these without gluten?
Yes! Several readers have reported success using both a gluten-free flour mix and almond flour.
How long do rhubarb brownies last?
Not long around here! Ha! If you have any left an hour after they come out of the oven, they will keep well in a covered container at room temperature for 3-4 days.
Can rhubarb brownies be frozen?
Yes! These brownies freeze very well. Cool them completely before you put them into your freezer. We like to freeze them wrapped individually so we can take out a few at a time. Let them thaw at room temperature before eating them.
Chocolate Rhubarb Brownies Recipe
Ingredients
- 1 cup granulated sugar
- ½ cup vegetable oil
- 2 large eggs
- 1 teaspoon vanilla
- ½ cup all-purpose flour (can sub gluten-free or almond flour)
- ⅓ cup cocoa powder
- ½ teaspoon baking powder
- ½ teaspoon sea salt
- 1 cup rhubarb (diced small)
- ½ cup dark chocolate chips
- ½ cup chopped walnuts or pecans
Instructions
- Preheat your oven to 375 degrees Fahrenheit. Line an 8×8 inch baking pan with parchment paper and lightly butter the top.
- In a medium-sized bowl, whisk the sugar, vegetable oil, eggs, and vanilla.1 cup granulated sugar, ½ cup vegetable oil, 2 large eggs, 1 teaspoon vanilla
- In a large bowl, whisk the flour, cocoa powder, baking powder, and sea salt.½ cup all-purpose flour, ⅓ cup cocoa powder, ½ teaspoon baking powder, ½ teaspoon sea salt
- Stir the wet ingredients into the dry ingredients and mix them until they are just incorporated. Add the rhubarb, chocolate chips, and nuts and mix until they are combined. The batter will be quite thick.1 cup rhubarb, ½ cup dark chocolate chips, ½ cup chopped walnuts or pecans
- Pour the batter into the prepared baking dish and spread it out so that it is even. Bake for 20-25 minutes, or just until a toothpick inserted into the middle comes out clean – see notes. Make sure not to overcook the brownies so they don't dry out.
- Remove the brownies from the oven and let them cool for at least 10 minutes. Cut them into 9 squares and … try not to eat them all at once!
Video
Notes
Nutrition
We have thoroughly tested this recipe for accuracy. However, individual results may vary. See our full recipe disclosure here.
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I tweaked the recipe. 8×8″ pan, 1 1/2 Cup flour and 2 cups rhubarb. The rest of the recipe was the same. Baked at 350 for 25 min.
These are awesome, moist, fudgy. Thanks for the recipe!
This is a great brownie recipe. With the price of butter going through the roof I am trying to find recipes that use oil instead. This was perfect.
I never would have thought to put rhubarb in brownies, but the contrast was delicious
Can you use honey or maple syrup instead of sugar?
We haven’t tried it so can’t so for sure. If you decide to experiment, let us know how it goes!
2 questions. If substituting with almond flour, is it the same quantity? And can I use coconut oil?
Yes to both!
Please edit the cocoa powder amount of the thick brownie section. I only put in 3T when it should be 1/3c plus 3T. Still very yummy, but more like a slightly chocolatey cake.
You’re right! Thank you for pointing that out. 🙂
What a combination, I never would have thought of rhubarb in brownies. Of course it doesn’t grow way down here in the caribbean, but I have a partial bag in the freezer to try this. Hoping my hubby doesn’t like them, hahaha. He is not a rhubarb fan, but he does love chocolate, so I may be in trouble and have to share. Being frozen, I would guess I will have to drain them?
Haha I’ll cross my fingers he doesn’t like them. 🙂
Yes, I would make sure to drain as much liquid from the thawed rhubarb as possible.
These are absolutely phenomenal! Every single person who tried them agreed with me. Even the couple people who don’t like rhubarb.
There’s not that bite of bitterness that you get with rhubarb cake. The flavors blend wonderfully and create a unique flavor of it own that’s just so hard to explain.
These brownies are excellent. I’ve used a different favorite recipe for many years, and these rhubarb brownies are now tied for the top favorite.
Excellent! I’ve made twice this week! Loved by the entire family. Almond flour makes them gf!
Great to know that it can be made with almond flour!!
These are really tasty but I cannot give higher than 3 stars because every time I make them they are soupy. I have tried increasing the amount of flour, increasing the time, raising the oven temperature but nothing i do makes them get to a fudgy cakey texture like the pictures. I have to basically scoop them up into a bowl. They are great this way over ice cream though.
I’m sorry to hear the recipe is not working out for you.
I finally got the recipe to work but had to bake for 40 minutes. I even tried a different brownie recipe and had the same issue. I think there’s too much moisture from the rhubarb to bake in a short amount of time.
I’m happy to hear that it worked out for you in the end!
AMAZING. Shared with everyone I know. GF all purpose flour worked great. Delicious!! New favorite recipe and best rhubarb one yet!
So awesome to know that GF flour worked great!
This was excellent! Really dark and delicious. I used frozen rhubarb that I thawed and chopped up. Two thumbs up!
Thanks, Penny!
This is really good. We love the rhubarb flavor.
That makes me so happy to hear! Thank you for coming back to let us know!
Has anyone tried this with stewed rhubarb (rather than chopped)? Thanks.
I haven’t but I think it would work. 🙂
I found this recipe a couple of years ago, right after we moved. It is now one of the things I look forward to about rhubarb season every year. I am contemplating taking some into work, but am not sure they’ll last that long.
That’s so great to hear! Rhubarb is so great, isn’t it?!
Hi Kristen, I volunteer at a community garden. Most of our organic produce goes to a central warehouse and is then distributed locally to pantries, soup kitchens, etc. I am a volunteer and we feed our volunteers who are working in the garden around lunchtime. I am always looking for creative ways to use what we grow. Plan on baking your rhubarb brownies to serve our volunteers during an upcoming plant sale fundraiser. I have lots of frozen rhubarb to experiment with. Will let you know how it goes. Thanks for sharing.
I hope they were a hit!