These rich chocolate rhubarb gooey brownie bars are soft, fudgy, and irresistible. Made with leftover rhubarb pulp from homemade rhubarb simple syrup and fresh chopped rhubarb for extra texture, they’re a delicious way to reduce food waste while creating a unique dessert.
The tart rhubarb balances the rich chocolate perfectly, while chocolate chips melt into every bite.
If you’re looking for a creative way to use leftover rhubarb pulp from making homemade rhubarb simple syrup, these Chocolate Rhubarb Gooey Brownie Bars deserve a spot on your baking list. Rich cocoa, melty chocolate chips, and tangy rhubarb come together in a dessert that’s both indulgent and surprisingly practical.
One of the best parts about homestead cooking is finding ways to make the most of every ingredient. After making a batch of rhubarb simple syrup, I couldn’t bring myself to throw away all that beautiful rhubarb pulp.
Instead, I folded it into a batch of chocolate brownie bars along with a handful of fresh chopped rhubarb. The result was a moist, fudgy treat with little bursts of tart rhubarb in every bite.
Why You’ll Love These Brownie Bars
- Great way to use leftover rhubarb pulp
- Rich, chocolatey, and extra moist
- Easy one-bowl style recipe
- Perfect balance of sweet and tart flavors
- Ready in about 40 minutes
- Freezer-friendly dessert
The Secret Ingredient: Rhubarb Pulp
After making rhubarb simple syrup, you’re left with soft, flavorful rhubarb pulp that’s packed with color and flavor. Rather than composting it, this recipe turns that leftover ingredient into a delicious dessert.
The pulp adds moisture and helps create the wonderfully gooey texture these bars are known for. Adding a small amount of fresh chopped rhubarb brings back some texture and a bright tart flavor that pairs beautifully with chocolate.
Chocolate Rhubarb Gooey Brownie Bars Recipe
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Equipment
Ingredients
- 2 Cups Fresh Rhubarb diced, or 1 Cup Rhubarb Pulp (leftover from making rhubarb simple syrup)
- 2 Tablespoons Water
- 1 Cup Granulated Sugar
- 1/2 Cup Vegetable Oil
- 2 Large Eggs
- 1 Teaspoon Vanilla Extract
- 1/2 Cup All-Purpose Flour
- 1/3 Cup Cocoa Powder
- 1/2 Teaspoon Baking Powder
- 1/2 Teaspoon Sea Salt
- 1/2 Cup Fresh Rhubarb finely chopped
- 1 Cup Chocolate Chips
Instructions
Making Rhubarb Pulp for Baking
- If you don’t have leftover rhubarb pulp on hand from a batch of rhubarb simple syrup or compote, you can easily prepare some in just a few minutes. Start by chopping 2 cups of fresh rhubarb into small pieces and placing them in a saucepan with 2 tablespoons of water. Cook over medium heat, stirring occasionally as the rhubarb softens.2 Cups Fresh Rhubarb, 2 Tablespoons Water
- Within 8 to 10 minutes, the rhubarb will break down into a thick, soft mixture. Once tender, remove it from the heat and allow it to cool slightly. For a smoother pulp, mash it with a fork or potato masher. If you prefer a little texture, leave some of the softened pieces intact.
- Measure the amount needed for your recipe and refrigerate any leftovers in an airtight container for up to 5 days. This homemade rhubarb pulp adds natural moisture, tangy flavor, and a subtle fruitiness to cakes, bars, muffins, and other baked treats.
Make the Gooey Brownies
- Preheat oven to 350°F. Line n 9 X 9-inch square baking pan with parchment paper for easy clean up. However, just lightly greasing works too.
- In a medium bowl, whisk together the sugar, vegetable oil, eggs, and vanilla until smooth.1 Cup Granulated Sugar, 1/2 Cup Vegetable Oil, 2 Large Eggs, 1 Teaspoon Vanilla Extract
- In a separate bowl, whisk together the flour, cocoa powder, baking powder, and sea salt.1/2 Cup All-Purpose Flour, 1/3 Cup Cocoa Powder, 1/2 Teaspoon Baking Powder, 1/2 Teaspoon Sea Salt
- Add the wet ingredients to the dry ingredients and stir just until combined.
- Fold in the rhubarb pulp, fresh chopped rhubarb, and chocolate chips.1/2 Cup Fresh Rhubarb, 1 Cup Chocolate Chips
- Spread the batter evenly into the prepared pan.
- Bake for 25 to 30 minutes, or until the edges are set and a toothpick inserted near the center comes out with a few moist crumbs.
- Allow the bars to cool completely before slicing into 16 squares.
Notes
Tips for Success
Don’t overmix the batter once the flour is added. Stir only until the ingredients are combined to keep the bars tender. Watch the baking time carefully. For gooey brownie bars, remove them when the center is mostly set but still has a few moist crumbs on a toothpick. Allow the bars to cool before slicing. This helps them hold their shape while maintaining that fudgy texture.Nutrition
A No-Waste Rhubarb Recipe
One of the best parts of homestead cooking is finding ways to use every part of an ingredient. After making rhubarb simple syrup, the leftover pulp still contains plenty of flavor and moisture. These brownie bars are a delicious way to transform what might otherwise be discarded into a family-favorite dessert.
- Rhubarb pulp from simple syrup adds moisture and natural flavor while reducing kitchen waste.
- Fresh rhubarb pieces provide bright tartness and a pleasant texture contrast.
- For extra chocolate flavor, sprinkle a few additional chocolate chips over the top before baking.
- Store covered at room temperature for up to 3 days or refrigerate for up to 1 week.
Variations
Extra Chocolate
Add an additional 1/4 cup chocolate chips on top before baking.
White Chocolate Twist
Substitute white chocolate chips for some or all of the dark chocolate chips.
Gluten-Free Option
Use your favorite 1-to-1 gluten-free flour blend.
How to Store
Store the brownie bars in an airtight container at room temperature for up to 3 days.
For longer storage, refrigerate them for up to 1 week. The flavor becomes even richer after a day in the refrigerator.
Freezing Instructions
These bars freeze beautifully. Wrap individual portions tightly and place them in a freezer-safe container or bag. Freeze for up to 3 months.
Thaw at room temperature for about an hour before serving.
Can I make these brownie bars without rhubarb pulp?
Yes. If you don’t have rhubarb pulp from making simple syrup, cook 1½ cups chopped rhubarb with 1–2 tablespoons water until soft and thick. Use 1 cup of the cooked rhubarb in place of the pulp. You can also substitute 1 cup of rhubarb compote or sauce. While fresh rhubarb can be used, cooked rhubarb produces the gooey, fudgy texture that makes these bars so special.
Can I Use Frozen Rhubarb?
Yes. Frozen rhubarb works well in this recipe. Thaw it before using and include any juices released during thawing, as the extra moisture helps create the soft, gooey texture of these brownie bars.
If using frozen rhubarb in place of the rhubarb pulp, cook the thawed rhubarb and its juices until soft and thick before adding it to the batter.
Why does rhubarb work with chocolate?
Rhubarb’s bright tartness helps balance the richness of chocolate, creating a dessert that feels less sweet and more complex.
Gooey Chocolate Bars
These Chocolate Rhubarb Gooey Brownie Bars are proof that some of the best recipes come from making use of ingredients you already have on hand. The combination of rich chocolate, tart rhubarb, and a wonderfully fudgy texture creates a dessert that’s both comforting and memorable.
If you’ve just finished making a batch of homemade rhubarb simple syrup, save that pulp and give these brownie bars a try. You might discover a new family favorite.
The rhubarb and chocolate are a delicious combination. And the gooey bars take this over the top.