Strawberry Rhubarb Crumble Bars are a perfect blend of sweet and tart, with juicy strawberries and tangy rhubarb nestled beneath a buttery, crumbly topping. These bars are like a little bite of sunshine, combining a soft jammy filling with a crunchy, crumbly crust that’s just so satisfying every time you take a bite.
I love making these bars when I want something that feels homemade but isn’t too fussy. The mix of strawberries and rhubarb always brings back memories of summer afternoons, and the crumble on top adds the perfect touch of buttery crispness. One tip I’ve learned is to use fresh rhubarb and give it a good toss with a bit of sugar before baking—that way, it loses some of its tartness but still keeps that lovely zing.
These bars are great to serve as an afternoon treat with a cup of tea or as a simple dessert after dinner. I often like to cut them into small squares and pack them up for picnics or to share with friends because they travel so well and taste even better the next day. Whether for a cozy get-together or just a little pick-me-up, these Strawberry Rhubarb Crumble Bars always brighten the day.
Key Ingredients & Substitutions
Rhubarb: Fresh rhubarb gives a nice tart kick. If you can’t find it, frozen rhubarb works too—just thaw and drain excess liquid before using. To soften its tartness, toss rhubarb with sugar and let it sit for 10 minutes.
Strawberries: Fresh strawberries add juicy sweetness. You can use frozen strawberries if fresh aren’t available, but drain them well to prevent sogginess. Alternatively, other berries like raspberries or blueberries also pair nicely.
Butter: Using unsalted butter helps control the salt level in the bars. If you prefer a dairy-free version, try coconut oil solidified but still soft—it adds a slight coconut flavor and keeps the crumble tender.
Flour: All-purpose flour is best for structure and texture. For a gluten-free option, use a 1-to-1 gluten-free baking flour blend, but note the crumb texture may be slightly different.
How Can I Make the Perfect Crumble Texture?
The crumble topping should be buttery and crisp, not dry or tough. Here’s how to get that:
- Start with softened butter, not melted — it blends better into the flour and sugar.
- Mix the butter and sugar until just combined; don’t overmix, or the texture will get dense.
- Reserve some dough from the crust to crumble on top—this keeps crust and topping consistent.
- Break crumbs into pieces by hand instead of squeezing tightly to keep chunks and a crispy texture.
- Bake until topping is golden brown and filling bubbles around the edges, signaling it’s cooked well.
Equipment You’ll Need
- 9×9 inch baking pan – I recommend this size because it fits all the layers perfectly and bakes evenly.
- Parchment paper – makes it super easy to lift out the bars once baked and helps with clean-up.
- Mixing bowls – for creaming butter, tossing fruit, and mixing dry ingredients; I like to have a few sizes on hand.
- Measuring cups and spoons – for accuracy when measuring sugar, flour, and liquids.
- Wooden spoon or spatula – great for mixing the dough and fruit filling without overworking.
Flavor Variations & Add-Ins
- Use frozen mixed berries instead of just strawberries for a colorful, fruity twist. They hold up well when thawed and drained.
- Add chopped nuts like walnuts or almonds on top of the crumble for extra crunch and flavor.
- Mix in a pinch of cinnamon or ginger in the fruit filling—these warm spices complement the tartness nicely.
- Swirl in a tablespoon of cream cheese or mascarpone into the filling before baking for a richer, creamier texture.
Strawberry Rhubarb Crumble Bars
Ingredients You’ll Need:
For the Crust and Crumble:
- 1 cup (2 sticks) unsalted butter, softened
- 1 cup granulated sugar
- 1 large egg
- 1 teaspoon vanilla extract
- 2 cups all-purpose flour
- 1/2 teaspoon baking powder
- 1/4 teaspoon salt
For the Filling:
- 2 cups fresh rhubarb, chopped into 1/2 inch pieces
- 2 cups fresh strawberries, hulled and chopped
- 3/4 cup granulated sugar
- 2 tablespoons cornstarch
- 1 teaspoon lemon juice
- Optional: 1/2 teaspoon vanilla extract or almond extract
Time You’ll Need:
Plan for about 15 minutes to prepare the crust, crumble, and filling, followed by 45-50 minutes of baking. Cooling the bars for at least 1 hour is important so the filling sets properly before cutting and serving.
Step-by-Step Instructions:
1. Prepare the Oven and Pan
Start by preheating your oven to 350°F (175°C). Line a 9×9-inch baking pan with parchment paper, leaving an overhang on the sides to help lift the bars out easily after baking.
2. Make the Crust and Crumble Dough
In a large bowl, cream together the softened butter and 1 cup sugar until the mixture is light and fluffy. Beat in the egg and vanilla extract until well combined. In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add these dry ingredients to your butter mixture until just combined. The dough will be crumbly.
3. Form the Crust and Prepare the Filling
Reserve about 1 cup of the dough for the crumble topping and press the remaining dough evenly into the bottom of the prepared pan to form the crust. In a medium bowl, mix the chopped rhubarb, strawberries, sugar, cornstarch, lemon juice, and optional vanilla or almond extract. Toss until the fruit is evenly coated.
4. Assemble and Bake
Spread the fruit mixture evenly over the crust, then crumble the reserved dough evenly on top. Bake for 45 to 50 minutes, or until the topping is golden brown and the fruit filling is bubbling.
5. Cool and Serve
Allow the bars to cool completely in the pan on a wire rack. This step helps the filling to set nicely. Once cooled, lift the bars out using the parchment overhang, place on a cutting board, and cut into squares. Serve plain or with whipped cream or vanilla ice cream for an extra treat.
Can I Use Frozen Strawberries and Rhubarb?
Yes! Just make sure to thaw and drain them well before using to avoid extra moisture that could make the bars soggy.
How Should I Store Leftover Bars?
Store leftovers in an airtight container in the fridge for up to 4 days. They also freeze well—wrap tightly and freeze for up to 2 months. Thaw in the fridge before enjoying.
Can I Make This Recipe Gluten-Free?
Absolutely! Substitute the all-purpose flour with a gluten-free flour blend in a 1:1 ratio. The texture might be slightly different but still delicious.
How Do I Prevent the Crumble from Getting Too Hard?
Use softened butter (not melted), and avoid overbaking. Check the bars around 45 minutes and look for a golden crumble and bubbling filling for the best texture.
