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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Lovely tasty moist recipe! I made it GF and DF
Love, love love these brownies, and it’s my go-to recipe as soon as I have more rhubarb in the garden than I need for pie. Have made them several times, but never seemed to be able to get them to hold together, baking longer at higher temp, etc. Today, I doubled the recipe, baked them in a 12.8″x9.5″ pan and turned the convection fan on – baked them @ 375 with convection for 30 min and a knife inserted in the middle came out clean. They are holding together nicely!
Hubby hates chocolate so I left out the cocoa powder and chocolate chips and doubled the rhubarb. Sorry to say we were both disappointed with the results. You’d think a whole cup of sugar would make it sweet, but it was extremely tart and unpalatable, and the texture was strange. Far from the tasty treat we were hoping for… not sure what went wrong!
I can imagine that omitting the chocolate and doubling the sour rhubarb would make pretty terrible brownies. I’d suggest trying this recipe as written; it’s a good one.
There are bazillions of online recipes for rhubarb bars, strawberry rhubarb bars, “brownies”, even and rhubarb or strawberry rhubarb cream cheese bars out there that should make your hubby smile, being he doesn’t like chocolate. I love anything made with chocolate or rhubarb, and look forward to trying this recipe, now that I have found it.
This cannot be a real comment. I refuse to believe you actually wrote this and meant it.
Is this a joke? You doubled the rhubarb (a tart flavour) and left out the chocolate (a key dry ingredient) and wonder why it’s tart with an odd texture?
🤦♀️🤦♀️🤦♀️🤦♀️🤦♀️🤦♀️🤦♀️ well ya you changed the recipe!!
Not sure what went wrong???? 🤣🤣🤣🤣🤣🤣🤣🤣
You should not negatively review someone until you have tried the recipe exactly as listed. It is unfair to the author. Your choice to substitute chocolate in a Brownie recipe is quite a wild thing. I would expect quite a wild result.
I think I know what went wrong…
Was really excited to make this recipe. After 20 minutes it was soft in the middle so I baked it an extra 5 minutes twice for a total of 30 minutes. Although they were still soft in the middle, I took them out to not risk burning the edges. I let the brownies cool for 10 minutes prior to cutting. Unfortunately both first pieces fell apart while being dished out. The mixture was yummy but overly gooey and the brownies did not keep their form. Not sure what I could do differently as I carefully measured the ingredients.
These were amazing!! Thank you!!
I baked these for nearly 50 min and the middle was far from baked. I used fresh rhubarb and followed the recipe to the T. My oven is brand new and the temp is accurate, per two different thermometers and everything else I have baked has turned out perfectly, with me typically baking it for less time than recipes call for. Should there be a variance based on location? The edges were done and tasted wonderful but anything beyond about 1.5 inches from the edge was a mushy mixture that would not bake. Huge bummer.
I’ve had the same problem every time I make them. The edges get dark but the inside never gets solid. Tried doubling the recipe too for a 9×13. Same issue. I won’t try them again.
Best recipe ever!!!!
Deeelicious! Everyone loved them, and no one could figure out the “secret” ingredient! Will be making them often!
Please if possible could i have recipe in grams. Tried making using cups but turned out to runny
We’re planning on adding metric measurements in the future, but at this point our recipes are only available as written.
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.
I had the same results, sadly. I quickly ran to the store to buy cookies for the event I was baking for. Maybe next time I will jump the temp to 425°
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!!