Rhubarb crumble bars are a tasty treat with a lovely mix of sweet and tangy rhubarb. They have a crunchy topping that pairs perfectly with the soft fruit filling!
Whenever I make these bars, I can’t help but munch on the delicious crumble. It’s just too hard to resist! 😋
I love how easy these bars are to whip up for a snack or dessert. Just layer the rhubarb mixture and crumble, bake, and enjoy with a scoop of ice cream on top!
Key Ingredients & Substitutions
Rhubarb: The star of this recipe! Fresh, tart rhubarb gives these bars their unique flavor. If rhubarb isn’t available, you can use frozen rhubarb; just thaw and drain excess moisture. Alternatively, you can mix in strawberries or raspberries for a different twist.
Oats: Old-fashioned rolled oats provide that perfect chewy texture. Quick oats can be a substitute, but they’ll create a softer crumble. I personally love the bite from the old-fashioned oats!
Butter: Unsalted butter is best for controlling the saltiness in your recipe. You can substitute with coconut oil or a dairy-free butter if you want a vegan option. Just know it may change the flavor slightly.
Cornstarch: This is essential for thickening the rhubarb filling. If you don’t have cornstarch on hand, you could use all-purpose flour or arrowroot starch, though cornstarch usually gives the best results.
Cinnamon: It’s optional but adds a nice warmth to the filling. I highly recommend it for an extra flavor boost, especially in the cooler months. If you’re not a fan, you can skip it with no problem!
How Do You Get the Right Texture for the Crumble Topping?
Achieving the perfect crumble topping is all about mixing and not overdoing it. Combine flour, oats, brown sugar, baking soda, and salt before pouring in the melted butter. The key is to stir until it forms a crumbly mixture, avoiding big clumps.
- Use a fork or your hands to gently mix everything together.
- Don’t overmix—stop when it resembles wet sand with little clumps.
This will ensure you’ll have a delightful texture; crumbly yet firm once baked. Remember to save some crumble for the topping after pressing the base into the pan!
How to Make Rhubarb Crumble Bars?
Ingredients You’ll Need:
For the Crumble Base and Topping:
- 1 1/2 cups all-purpose flour
- 1 cup old-fashioned rolled oats
- 1 cup light brown sugar, packed
- 1/2 teaspoon baking soda
- 1/4 teaspoon salt
- 3/4 cup unsalted butter, melted
For the Rhubarb Filling:
- 3 cups rhubarb, chopped into small pieces
- 1 cup granulated sugar
- 3 tablespoons cornstarch
- 1 teaspoon vanilla extract
- Optional: 1/2 teaspoon ground cinnamon (to add warmth to filling)
How Much Time Will You Need?
This delightful dessert will take about 20 minutes to prepare, plus an additional 40 to 45 minutes to bake, and around 1 to 2 hours to cool completely. So, in total, you’re looking at roughly 2 to 3 hours from start to enjoying your sweet treats!
Step-by-Step Instructions:
1. Preheat Oven & Prepare Pan:
First, let’s get things heated up. Preheat your oven to 350°F (175°C). While that’s warming up, take a 9×13 inch baking pan and line it with parchment paper. Leave some extra paper hanging over the sides for easy lifting later on.
2. Make the Crumble Base and Topping:
In a large mixing bowl, combine the flour, rolled oats, light brown sugar, baking soda, and salt. Stir everything together well. Then pour in the melted butter and mix just until it’s combined and crumbly. You want it to look like damp sand!
3. Press Base:
Now, reserve about 1 1/2 cups of your crumble mixture for the topping. Press the rest firmly into the bottom of your prepared pan. This will be your solid base layer!
4. Prepare Rhubarb Filling:
In another bowl, toss together the chopped rhubarb, granulated sugar, cornstarch, vanilla extract, and cinnamon (if you’re using it). Make sure the rhubarb gets well coated with the mixture.
5. Assemble Bars:
Spread the rhubarb filling evenly over the base layer in the pan. After that, sprinkle the reserved crumble mixture evenly over the top of the rhubarb layer.
6. Bake:
Now it’s time to bake! Place your pan in the oven and bake for 40 to 45 minutes. Keep an eye on it; you’re looking for a golden brown topping with bubbling filling. The aroma will be fantastic!
7. Cool and Slice:
Once baked, take the pan out and let it cool completely on a wire rack for about 1 to 2 hours. This helps the filling set properly. When it’s cool, use the parchment overhang to lift the bars out of the pan and cut them into squares.
8. Serve:
Your rhubarb crumble bars are ready to enjoy! They’re delicious on their own, or you can serve them with a scoop of vanilla ice cream or a dollop of whipped cream for that extra treat!
These bars have a lovely blend of buttery oat crumble, a tart-sweet rhubarb filling, and a crisp topping that’s simply delightful—perfect for spring celebrations!
Can I Use Frozen Rhubarb for This Recipe?
Absolutely! Just make sure to thaw and drain the frozen rhubarb before using it in the recipe. This helps prevent excess moisture in your filling, which can make the bars soggy.
Can I Make These Bars Vegan?
Yes, you can! Substitute the unsalted butter with coconut oil or a dairy-free butter alternative. For the granulated sugar, look for a vegan brand to keep it cruelty-free.
How Do I Store Leftover Bars?
Store any leftover rhubarb crumble bars in an airtight container in the refrigerator for up to 3 days. You can also freeze them for longer storage; just wrap them tightly in plastic wrap and place them in a freezer bag. They should keep for about 2-3 months!
What Can I Substitute for Cornstarch?
If you run out of cornstarch, you can use all-purpose flour or arrowroot starch as substitutes. Just keep in mind that cornstarch typically creates a smoother filling, so consider that when choosing your substitute.
