Strawberry Rhubarb Crumble Bars are a delightful treat that bring together the sweet juiciness of strawberries and the tart punch of rhubarb, all wrapped up in a crumbly, buttery crust. These bars have a perfect balance of flavors and textures, with a crisp, golden topping that melts in your mouth and a filling that’s both fruity and refreshing.
I love making these bars because they feel like a little bit of summer in every bite. The combination of strawberries and rhubarb always reminds me of warm days and family gatherings. One of my favorite tips is to gently simmer the fruit filling before assembling the bars—it helps thicken things up and keeps the crumble from getting soggy. Plus, it helps the flavors really blend together.
These bars are so versatile—you can enjoy them as a snack with a cup of tea, serve them for dessert after dinner, or even pack them for a picnic. I often cut them into small squares to share with friends, and they never stick around for long. If you like a little extra crunch, sprinkling a bit of coarse sugar on top before baking adds a nice finishing touch. They’re simple to make and always a crowd-pleaser!
Key Ingredients & Substitutions
Strawberries and Rhubarb: These two give the bars their classic sweet-and-tart flavor. You can use frozen fruit if fresh isn’t available—just thaw and drain excess juice. If rhubarb is hard to find, try substituting with tart apples for a similar tang.
Butter: Real butter is key for that rich, crumbly texture in both the crust and topping. For a dairy-free option, use a vegan butter or coconut oil, but expect a slight change in flavor and texture.
Rolled Oats: They add chewiness and a bit of heartiness to the crumble. If you need gluten-free bars, use certified gluten-free oats and gluten-free flour instead of all-purpose flour.
Cornstarch: This thickens the fruit filling so it’s not too runny. Arrowroot powder can be a good substitute if you don’t have cornstarch on hand.
How Do You Get the Crust and Topping Perfectly Crumbly?
The key here is mixing the cold butter just right into the dry ingredients:
- Use cold, cubed butter straight from the fridge.
- Cut the butter into the flour and oats with a pastry cutter, two forks, or your fingertips until you have pea-sized chunks and crumbly texture.
- Avoid overmixing—some larger chunks make for a tender crunch.
- Press two-thirds of this mixture firmly into the pan for the base to help it hold together after baking.
The remaining crumbs are sprinkled loosely on top so they crisp up nicely in the oven. This contrast between the firm bottom and crumbly top is exactly what makes these bars so tasty!
Equipment You’ll Need
- 9×9 inch baking pan – I use this size to keep the bars cozy and thick, and it fits easily in the oven.
- Parchment paper – makes removing the bars simple and prevents sticking.
- Mixing bowls – for preparing the crust, topping, and filling; I prefer two different sizes for convenience.
- Pastry cutter or forks – helps cut in the butter until the mixture resembles crumbs; I find a pastry cutter easier.
- Wooden spoon or spatula – to stir the fruit filling; I like a spatula for gentle mixing.
- Measuring cups and spoons – for accuracy, ensuring the right flavor balance.
Flavor Variations & Add-Ins
- Replace strawberries with blueberries or raspberries for different fruity flavors.
- Add shredded coconut or chopped nuts in the crumble topping for extra crunch.
- Stir a pinch of cinnamon or ginger into the fruit filling for warm spice notes.
- Mix in a handful of chopped apples or pears if you want a softer, sweeter fruit version.
Strawberry Rhubarb Crumble Bars
Ingredients You’ll Need:
For the Crust and Crumble Topping:
- 1 1/2 cups all-purpose flour
- 1 cup old-fashioned rolled oats
- 1/2 cup granulated sugar
- 1/2 cup light brown sugar, packed
- 1/2 teaspoon baking soda
- 1/4 teaspoon salt
- 3/4 cup (1 1/2 sticks) unsalted butter, cooled and cut into cubes
For the Strawberry Rhubarb Filling:
- 2 cups fresh strawberries, hulled and quartered
- 2 cups rhubarb, chopped into 1/2-inch pieces
- 3/4 cup granulated sugar
- 3 tablespoons cornstarch
- 1 tablespoon fresh lemon juice
- 1 teaspoon vanilla extract
Time Needed:
This recipe takes about 20 minutes to prepare, 35 to 40 minutes baking time, plus another 2 hours to cool completely so the filling can set nicely.
Step-by-Step Instructions:
1. Preheat and Prepare Your Pan:
Set your oven to 350°F (175°C). Line a 9×9-inch baking pan with parchment paper, leaving some overhang on the sides to help you lift the bars out easily once they’re done.
2. Make the Crust and Topping:
In a large bowl, mix together the flour, oats, granulated sugar, brown sugar, baking soda, and salt. Add the cold, cubed butter. Use a pastry cutter, two forks, or your fingers to blend until the mix looks like coarse crumbs with some pea-sized bits.
3. Form the Crust:
Press about two-thirds of the crumb mixture evenly into the bottom of your prepared pan. Save the rest of the crumbs to sprinkle over the fruit filling later.
4. Bake the Crust:
Bake the crust for 12-15 minutes, until it just starts turning golden. Then remove it from the oven and set it aside.
5. Prepare the Filling:
In a medium bowl, gently toss the strawberries and rhubarb with the sugar, cornstarch, lemon juice, and vanilla extract. Make sure the fruit is nicely coated.
6. Assemble the Bars:
Spread the fruit filling evenly over your prebaked crust. Then sprinkle the reserved crumb topping evenly on top.
7. Bake Until Golden:
Return the pan to the oven and bake for another 35-40 minutes, until the topping is golden brown and the filling is bubbly.
8. Cool and Slice:
Allow the bars to cool completely in the pan on a wire rack—this usually takes about 2 hours to let the filling set perfectly. Use the parchment paper overhang to lift the bars out, then slice into squares.
9. Serve and Store:
Enjoy your bars fresh, or keep them in an airtight container in the fridge for up to 4 days. They’re lovely with a hot cup of tea or a scoop of creamy vanilla ice cream!
Can I Use Frozen Strawberries and Rhubarb for the Filling?
Yes, you can! Just make sure to thaw them completely and drain any excess liquid before mixing with the sugar and cornstarch to avoid a soggy filling.
How Should I Store Leftover Bars?
Store leftover bars in an airtight container in the refrigerator for up to 4 days. Let them come to room temperature or warm slightly before serving for the best texture and flavor.
Can I Make These Bars Ahead of Time?
Absolutely! You can bake them a day in advance and keep them chilled. Just be sure to cool them completely before storing to keep the topping crisp.
What Can I Substitute for Rhubarb?
If rhubarb is unavailable, try using tart apples or cranberries for a similar tartness, adjusting the sugar slightly to balance the flavors.
