Mastering rhubarb squares
Rhubarb squares are a delightful dessert that perfectly balances the tartness of rhubarb with a buttery, crumbly crust and topping. This recipe stands out because it offers a vibrant filling made by simmering diced rhubarb with cane sugar, lemon juice, and vanilla extract, which is then pureed into a smooth, luscious layer. The crust and topping combine wholesome rolled oats, all-purpose flour, brown sugar, and warm spices like cinnamon and freshly grated nutmeg. Blending these dry ingredients with vegan butter creates coarse crumbs that add a tender, multi-textured contrast to the filling.
What makes rhubarb squares an excellent choice for home cooks is their simplicity and versatility. The preparation involves straightforward steps, and the final product is not only visually appealing with a golden oat crust and vibrant pink filling but also naturally vegan when made with plant-based butter and can be gluten-free if oat and flour substitutes are used. This treat appeals to various audiences, from those seeking comfort desserts to those wanting healthier or plant-based options, thanks to its wholesome ingredients and customizable nature.
Serving rhubarb squares with a scoop of vanilla ice cream or a dollop of whipped cream creates a charming dessert with a flavorful contrast between warmth, creamy richness, and tart fruitiness, making it perfect for gatherings, potlucks, or personal indulgence.
Benefits and Advantages of rhubarb squares
Rhubarb squares combine ease of preparation with nutritional benefits and a unique flavor profile that sets them apart. The recipe’s use of rhubarb delivers a tangy punch rich in vitamins and antioxidants, particularly vitamin C and fiber, which promote digestive health and boost immunity. According to health benefits of rhubarb, this ingredient supports detoxification and helps regulate blood sugar levels, making it a smart choice for health-conscious bakers.
From a culinary perspective, the dual-layer crust and crumb topping featuring oats, flour, brown sugar, and warming spices not only provide a comforting aroma but also contribute beneficial whole grains and minerals. Vegan butter used in the recipe offers a dairy-free fat source for those avoiding animal products without compromising flavor or texture.
This recipe is notably flexible; it can be adjusted to taste by modifying sugar levels to maintain the fresh tartness of rhubarb or by incorporating other seasonal fruits like strawberries or blueberries for additional sweetness and variety. These bars are ideal for make-ahead desserts, retaining their quality over several days and freezing well for longer storage, which is convenient for busy households or event planning.
Rhubarb squares stand out as a wholesome, flavorful, and visually appealing dessert that satisfies sweet cravings while offering healthful ingredients and practical cooking ease.

Essential Ingredients for rhubarb squares
- 1 pound diced rhubarb
- ½ cup cane sugar
- ¼ cup water
- 1 tablespoon lemon juice
- ½ teaspoon vanilla extract
- 1 ½ cups all-purpose flour
- 1 ½ cups rolled oats
- 1 cup brown sugar
- 1 teaspoon cinnamon
- ½ teaspoon baking soda
- ½ teaspoon salt
- ¼ teaspoon freshly grated nutmeg
- ¾ cup softened vegan butter
These ingredients serve distinct purposes: rhubarb provides the tart filling, sweetened with cane sugar and brightened by lemon juice and vanilla; the crust and crumb layers combine oats and flour for texture, brown sugar for sweetness, and spices for warmth. Vegan butter binds the dry ingredients to create the crumbly topping and base crust. Using vegan butter also makes the recipe accessible to those following plant-based diets, and choosing gluten-free flour and oats can easily adapt it for gluten sensitivities.
Dietary Substitutions to Customize Your rhubarb squares
Rhubarb squares offer several opportunities for dietary customization to accommodate various health needs and ingredient preferences:
- Gluten-Free: Replace all-purpose flour with gluten-free flour blends or oat flour to maintain the crumbly texture without gluten. Ensure rolled oats are certified gluten-free to avoid cross-contamination.
- Vegan: The recipe already uses vegan butter, but if further veganization is desired, ensure that the sugar used is vegan-friendly. Alternative plant-based sweeteners like maple syrup can be used in small quantities but may affect texture.
- Low Sugar: To preserve the tartness of rhubarb, reduce the cane sugar in the filling and adjust the brown sugar in the crust accordingly. This allows more of the fruit’s natural flavor to shine while keeping sweetness in balance.
- Alternative Thickeners: Use tapioca starch instead of cornstarch or flour as the thickening agent in the filling for a clearer set and a slightly different mouthfeel, ideal for those preferring a glossier finish.
- Other Fruits: Add or substitute fruits such as strawberries, blueberries, or diced apples to tailor the flavor and nutritional profile. This also enables seasonal adaptability and enhanced sweetness.
These substitutions make rhubarb squares a flexible and inclusive dessert option adaptable to diverse dietary requirements and taste preferences. For tips on vegan crusts, visit how to make vegan butter crusts. For seasoning ideas on oats and spices, see tips for baking with oats and spices.

How to Prepare the Perfect rhubarb squares: Step-by-Step Guide
- First Step: Preheat your oven to 350°F (180°C) and grease a 9 by 13-inch pan thoroughly, or line it with parchment paper for easy removal.
- Second Step: Prepare the rhubarb filling by combining 1 pound of diced rhubarb, ½ cup cane sugar, ¼ cup water, and 1 tablespoon lemon juice in a saucepan.
- Third Step: Bring the mixture to a boil over medium heat, then reduce to a simmer and cook for about 20 minutes, stirring occasionally until the rhubarb is soft and tender.
- Fourth Step: Remove the pot from heat, stir in ½ teaspoon vanilla extract, and allow it to cool slightly before blending the mixture until smooth with an immersion blender or food processor.
- Fifth Step: In a large mixing bowl, combine 1 ½ cups all-purpose flour, 1 ½ cups rolled oats, 1 cup brown sugar, 1 teaspoon cinnamon, ½ teaspoon baking soda, ½ teaspoon salt, and ¼ teaspoon freshly grated nutmeg.
- Sixth Step: Add ¾ cup softened vegan butter to the dry ingredients and mix with your fingers or a pastry cutter until coarse crumbs form.
- Seventh Step: Reserve 1 cup of the crumb mixture for the topping, then press the remaining crumbs firmly into the bottom of the prepared pan to create the crust.
- Eighth Step: Spread the cooled rhubarb filling evenly over the crust layer in the pan.
- Ninth Step: Sprinkle the reserved crumb topping evenly over the rhubarb filling.
- Tenth Step: Bake the rhubarb squares for 35 to 40 minutes or until the topping is golden and the filling is set.
- Eleventh Step: Allow the rhubarb squares to cool completely in the pan before cutting into bars for serving.

Mastering rhubarb squares: Advanced Tips and Variations
Tips for Perfect Rhubarb Squares
- Adjust the sugar quantity according to your taste preference to maintain the natural tartness of the rhubarb.
- Use parchment paper in the pan with an overhang for effortless removal of the bars after baking.
- Chill the mixture slightly before baking to help the crumb topping maintain its texture.
- Add a splash of lemon zest to the rhubarb filling for a bright, citrusy accent.
Variations to Try
- Combine rhubarb with other fruits such as strawberries, blueberries, or apples for a mixed fruit square.
- Substitute cornstarch with tapioca starch in the filling to achieve a clearer set and glossy finish.
- Add shredded coconut or chopped nuts to the crumb topping for extra texture and flavor complexity.
- Experiment with adding spices such as cardamom or ginger to complement rhubarb’s tartness.
How to Store rhubarb squares: Best Practices
Once baked and cooled, rhubarb squares can be stored in an airtight container at room temperature for up to two days to keep the crumb crust crisp. For longer storage, refrigerate the bars where they will stay fresh for up to five days. Ensure the container is sealed tightly to prevent moisture absorption.
For freezing, wrap individual bars or the whole pan tightly in plastic wrap followed by aluminum foil, then place in a freezer-safe bag or container. Freeze for up to three months. Thaw in the refrigerator overnight before serving to maintain the texture and flavor integrity.
When reheating, warm the squares briefly in an oven set to low heat (around 300°F) for a few minutes to revive the crumbly texture without drying out the filling.
Nutritional Value of rhubarb squares
Nutrient | Approximate Amount per Serving |
---|---|
Calories | 220-280 kcal |
Carbohydrates | 35-45 g |
Fat | 8-12 g |
Protein | 2-4 g |
Fiber | 3-5 g |
Sugars | 15-20 g |
Rhubarb squares bring a balance of carbohydrates from the oats and sugar, healthy fats mainly from vegan butter, and a moderate amount of fiber courtesy of rolled oats and rhubarb. The natural tartness of rhubarb contributes to lower sugar levels compared to other sweet desserts. These bars make a nutrient-rich option when served in moderation and paired with fresh fruit or yogurt for added benefits.

FAQs: Frequently Asked Questions About rhubarb squares
What ingredients do I need to make rhubarb squares?
You will need 1 pound of diced rhubarb, ½ cup cane sugar, ¼ cup water, 1 tablespoon lemon juice, ½ teaspoon vanilla extract for the filling. For the crust and crumb topping, use 1 ½ cups all-purpose flour, 1 ½ cups rolled oats, 1 cup brown sugar, 1 teaspoon cinnamon, ½ teaspoon baking soda, ½ teaspoon salt, ¼ teaspoon nutmeg, and ¾ cup softened vegan butter. These ingredients combine to create a flavorful and balanced dessert.
How do I make the rhubarb filling for squares?
Cook diced rhubarb with cane sugar, water, and lemon juice in a saucepan over medium heat until softened, about 20 minutes. You can use cornstarch or tapioca starch as a thickener if desired. After cooking, add vanilla extract and blend the mixture until smooth. Adjust sugar to taste, especially if you prefer a more tart filling.
What type of crust works best for rhubarb squares?
A crust made from a mixture of flour, rolled oats, and brown sugar combined with softened vegan butter creates a buttery, slightly crumbly base and topping that balances the tangy rhubarb filling perfectly. Vegan butter can be used to keep the recipe plant-based without compromising texture.
Can I replace cornstarch with another thickener in rhubarb squares?
Yes, tapioca starch is an excellent alternative to cornstarch. Use slightly less tapioca starch, about ¾ of the amount of cornstarch. Tapioca gives the filling a clearer, glossy set and a slightly different texture, which some prefer for fruit bars.

Irresistible Rhubarb Bar Treats with Crumbly Topping: Perfect for Sweet Delights
- Total Time: 1 hour 15 minutes
- Yield: Approximately 16 bars 1x
- Diet: Vegan
Description
🍰 Experience the delightful combination of tangy rhubarb and crumbly topping in these irresistible Rhubarb Bar Treats.
🌿 Perfect for sweet indulgences, these bars offer a unique blend of textures that are sure to satisfy your dessert cravings.
Ingredients
1 pound diced rhubarb
1/2 cup cane sugar
1/4 cup water
1 tablespoon lemon juice
1/2 teaspoon vanilla extract
1 1/2 cups all-purpose flour
1 1/2 cups rolled oats
1 cup brown sugar
1 teaspoon cinnamon
1/2 teaspoon baking soda
1/2 teaspoon salt
1/4 teaspoon freshly grated nutmeg
3/4 cup softened vegan butter
Instructions
1. Preheat the oven to 350°F (180°C) and grease a 9 by 13-inch pan.
2. Prepare the rhubarb filling by boiling rhubarb, sugar, water, and lemon juice; simmer for 20 minutes until softened, then add vanilla extract.
3. After cooling slightly, blend the rhubarb filling until smooth.
4. In a bowl, mix flour, oats, brown sugar, cinnamon, baking soda, salt, and nutmeg.
5. Blend with softened vegan butter until coarse crumbs form. Reserve 1 cup of the crumb mixture for the topping.
6. Press the remaining mixture into the pan.
7. Spread the cooled rhubarb filling over the crust and top with the reserved crumbs.
8. Bake for 35 to 40 minutes until set.
9. Allow to cool before slicing into bars.
Notes
🍯 Adjust sugar to your preference to maintain rhubarb’s tartness.
📃 Use parchment paper in the pan for easy removal.
🍎 Try adding fruits like strawberries, blueberries, or apples for variety.
- Prep Time: 15 minutes
- Cooling Time: 20 minutes
- Cook Time: 35 to 40 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 bar
- Calories: 180
- Sugar: 12 grams
- Sodium: 85 mg
- Fat: 7 grams
- Saturated Fat: 1 gram
- Unsaturated Fat: 5 grams
- Trans Fat: 0 grams
- Carbohydrates: 27 grams
- Fiber: 2 grams
- Protein: 2 grams
- Cholesterol: 0 mg