Dark Chocolate Rhubarb Brownies
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!
If you love rhubarb as much as we do, also try our strawberry rhubarb cobbler, rhubarb strawberry chia jam, and Strawberry Rhubarb Pie with Extra Flaky Pie Crust.
This recipe was originally published back in 2014. We've updated the post with some new photos and more information but the recipe remains exactly the same.
This is the brownie recipe we make every spring. The best part of these brownies is the little bits of moist rhubarb. They're not overly tart like you're probably thinking. It's the texture that I really amazing. Rhubarb does for these brownies what carrots do for carrot cake. Trust us, it just works.
But the rhubarb flavor is in every bite, too. And again, it just works. The tartness of the rhubarb marries perfectly with the sweet brownies. Don't expect these brownies to last long; they're delicious!
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!
Full recipe instructions in the recipe card below.
How to make extra thick brownies
Sometimes nothing but extra thick brownies will do. If that's what you're craving, increase the recipe by half. 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, you'll want to bake them for an extra five minutes.
Can I make these gluten-free?
Yes! Several readers have commented that they've had success with using both gluten-free flour mix and almond flour.
How long do rhubarb brownies last?
Not long around here! Ha! In the unlikely event that you have any left an hour after they come out of the oven, know that 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.
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Chocolate Rhubarb Brownies
If you love this recipe as much as we do, let us know with a 5-star rating!
- 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
- Preheat your oven to 375 degrees. 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. 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!
I am so excited to make this recipe! Is it possible to not use chocolate chips? Thank you!
You can omit them if you’d like!
Couldn’t wait to try this recipe sounded so good! I used mostly fresh rhubarb and had to add a little frozen to make the amount needed! I feel like it was baking forever, at least 40 minutes and yet I found it to be very mushy. What did I do wrong?
Did you thaw the frozen rhubarb first? If not, that would have added a lot of moisture to the recipe which would cause it to be very soft.
Hi could you use a boxed brownie for these .
We haven’t tested adding rhubarb to boxed mix so I can’t say for sure. If you decide to try it, let us know how it goes!
Very good. Will definetly make again and share recipe.
Excellent. So easy. Made just the way the recipe is written. Making another batch to freeze. ❤️
Very delicious! We have an abundance of rhubarb every year and this is a great way to enjoy it. Picked fresh today and made them for dessert. Thank you!!
I live in the rhubarb state, Alaska. I have made a lot of great rhubarb recipes but never with chocolate. After reading the great comments I felt I had no choice but to make these. I double the recipe and baked for 42 mins. I used frozen rhubarb, coconut oil in a 9×13 pan. Amazing and super moist. I will be writing this recipe out onto an index card so I will also be able to find it.
Best brownie ever! The first time my daughter and I made these we put way too much cocoa in (twice as much) and cut the rhubarb too small, they came out nearly black and tasted very bitter and ended up in the bin .My daughter reduced the cocoa to 50g and sliced the rhubarb instead of dicing and they came out so gooey and delicious! She made them for her Food tech G.C.S.E yesterday. The teacher commented that they were the best brownie she’s ever had and came back again for another slice. Thank you! We will always use this recipe!!
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!
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!
I like to try out new recipes and when I realised just how much rhubarb I had in the freezer thought I’d best do something with it. I’d been searching for the perfect recipe and came across your dark chocolate rhubarb brownie recipe. And Oh.My!
Lucky you to find rhubarb in your freezer! I can’t wait for spring to come so I can get more. I’m so happy to hear the recipe was a hit!
Would self raising flour work in this recipe
I’ve honestly never bought self-rising flour before. As far as I know, it simply contains a leavening agent such as baking powder. Is that correct? If it is, you should be able to use it and omit the baking powder. 🙂
Favorite go-to brownie recipe when rhubarb season hits for 2 years running!
That’s so great to hear! Hooray!!
If I wanted to make in a 9×13 pan would I doubt the recipe?
That would work!
Hi, i baked this pie yesterday and find difficulties to melt the sugar- could you explain how to prepare first part of the second point of the instruction?
All you need to do is whisk the sugar with the oil, eggs, and vanilla. No need to melt it. 🙂
375 degrees?? That seems rather high
375 degrees Fahrenheit! If you’re converting from Celsius it would be 190 degrees. 🙂
I never bake but was asked to for a party tomorrow. Of course, had to sample the final product and although they are crumbly – they taste amazing!! Thank you for this great recipe!
Nice blog but way too many ads. Takes too long to get to the recipe.
Thank you so much for your feedback. I’m trying out a new company to manage my ads and so your feedback is really valuable. Thank you!
Finally a rhubarb brownie recipe I’ll want to bake again and again and again! Thank you so much for sharing this delicious recipe. Five stars for taste and good looks 🙂 Got lots of compliments!
I’m so happy you like the recipe as much as I do! <3 rhubarb. 🙂
These have to be the best brownies I have ever baked. The tartness from the rhubarb really balances the brownies. They were perfection in a pan. I have made this recipe 3 times since trying it on Sunday.
You’re comment just put a big smile on my face! So happy you like the brownies!!
Made these today! I added dark chocolate pomegranate nibs instead of nuts and it went well. Thanks for the recipe!
Can I exchange the all purpose flour for gluten free flour. I am thinking a combination of brown rice.,tapioca and almond flours.
I haven’t tried it with gluten free flour myself but I have heard from other readers that works fine for them. 🙂
Is it just as good to use regular chocolate chips?
Absolutely you can use regular chocolate chips. It will probably be a touch sweeter, but it will still be so good. 🙂
It looks like you and your partner in crime really enjoyed the brownies. Well, what can I say? These brownies are wonderful. I wouldn’t mind eating it all by myself. Thanks for a great recipe!
Ha ha we totally did! It was a little embarrassing how many we ended up eating. But that’s what Aunties are for, right?!
These are indeed great! I made them last night and then put them in the freezer so we wouldn’t be tempted to inhale them – and guess what – they are good right out of the freezer! Foiled again! This will be a must make every time it is rhubarb season.
Good to know they are great out of the freezer! Or maybe not since the only reason I’d be putting them there is to prevent myself from eating all of them again 😉
Looks delicious! Thanks for sharing!