Jammy Strawberry Rhubarb Bars (Buttery Crumble)

The Best Strawberry Rhubarb Crumb Bars (Easy Recipe!)

Estimated reading time: 7–9 minutes  |  Prep time: 25 minutes  |  Total time: 3 hours 15 minutes (includes cooling)

Key Takeaways

• Perfect Flavor Balance: Experience the delightful contrast of sweet strawberries and tart rhubarb, creating a perfectly balanced fruit filling that isn’t overly sweet.
• Irresistible Texture: This recipe delivers a thick, buttery oat crumble that serves as both a sturdy base and a golden-brown, slightly crunchy topping, providing the ultimate texture in every bite.
• Beginner-Friendly Recipe: With simple, straightforward steps, this is a family-friendly dessert that even novice bakers can master. No special techniques required!
• Make-Ahead & Freezer-Friendly: These bars are an excellent make-ahead dessert. They store beautifully in the refrigerator for days and freeze perfectly for up to three months.
• Versatile Serving Options: Delicious on their own, or elevate them by serving warm with a scoop of vanilla ice cream for a truly decadent treat perfect for any occasion.

Why You’ll Love This Strawberry Rhubarb Crumb Bars Recipe

Get ready to fall in love with the ultimate spring and summer dessert: our incredible Strawberry Rhubarb Crumb Bars. This simple recipe captures the timeless combination of sweet, juicy strawberries and bright, tangy rhubarb, all nestled between a buttery, oat-filled crumble. The base is firm yet tender, the fruit filling is jammy and vibrant, and the crumbly topping is baked to a perfect golden-brown crisp. It’s a symphony of flavors and textures that will have everyone asking for the recipe.

What makes this homemade recipe truly special is its simplicity and versatility. It’s an easy dessert to whip up for a backyard barbecue, a family gathering, or just a quiet afternoon treat with a cup of tea. The process is straightforward, using common pantry staples to create something that tastes professionally made. Unlike a traditional pie, these bars are portable, easy to serve, and don’t require any fussy pastry work. The generous oat crumble does double duty as both the base and topping, saving you time without sacrificing flavor.

Whether you’re a seasoned baker or just starting, these Strawberry Rhubarb Crumb Bars are foolproof. We’ll guide you through every step, from cooking the perfect fruit filling to achieving that irresistible crumbly texture. Plus, we’ve included plenty of tips, variations, and storage advice to ensure you get perfect results every single time. Prepare to make this your new go-to recipe for rhubarb season!

Ingredients You’ll Need

Using high-quality ingredients is the key to creating the most delicious Strawberry Rhubarb Crumb Bars. Here’s what you’ll need to gather:

For the Jammy Strawberry Rhubarb Filling

• Fresh Rhubarb: 3 cups (360g), trimmed and chopped into 1/2-inch pieces. This provides the signature tartness.
• Fresh Strawberries: 3 cups (450g), hulled and quartered. They bring natural sweetness and a beautiful red hue.
• Granulated Sugar: 1 cup (200g), to balance the tart fruit and help the filling set.
• Cornstarch: 1/4 cup (32g), the essential thickener that creates a perfect, sliceable consistency.
• Fresh Lemon Juice: 1 tablespoon, to brighten the fruit flavors and prevent the filling from being overly sweet.
• Pure Vanilla Extract: 1 teaspoon, for a touch of warm, aromatic depth.

For the Buttery Oat Crumble Base and Topping

• All-Purpose Flour: 3 cups (360g), the structural foundation for the crumble.
• Old-Fashioned Rolled Oats: 1 1/2 cups (150g), for a chewy texture and nutty flavor. Do not use quick oats.
• Light Brown Sugar: 1 1/2 cups (330g), packed. It adds moisture, sweetness, and a hint of caramel flavor.
• Baking Powder: 1 teaspoon, to give the crumble a slight lift and a more tender texture.
• Ground Ginger: 1 teaspoon (optional), a wonderful warming spice that pairs beautifully with rhubarb.
• Salt: 1/2 teaspoon, to enhance all the other flavors.
• Unsalted Butter: 1 1/2 cups (340g), cold and cut into 1/2-inch cubes. Cold butter is critical for a crumbly, tender texture.

Equipment Needed

• 9×13 inch (23×33 cm) baking pan
• Parchment paper
• Large mixing bowl
• Medium saucepan
• Whisk
• Spatula or wooden spoon
• Pastry blender or your fingertips
• Measuring cups and spoons
• Wire cooling rack

Step-by-Step Instructions

Follow these simple steps to bake the perfect batch of fruit crumb bars from scratch. We’ve broken it down into three easy stages.

Part 1: Prepare the Pan and Fruit Filling

1. Step 1: Preheat and Prepare the Pan. First, preheat your oven to 375°F (190°C). Then, line a 9×13 inch (23×33 cm) baking pan with parchment paper. Make sure to leave a 2-inch overhang on the two longer sides. Consequently, this will create “handles” to easily lift the bars out later for clean slicing.
2. Step 2: Combine Filling Ingredients. In a medium saucepan, combine the chopped rhubarb, quartered strawberries, granulated sugar, and cornstarch. Stir everything together with a spatula until the fruit is well-coated and the cornstarch is dissolved. Next, stir in the fresh lemon juice and pure vanilla extract for extra brightness and flavor.
3. Step 3: Cook the Filling. Place the saucepan over medium heat. Bring the mixture to a gentle simmer, stirring frequently to prevent it from sticking to the bottom of the pan. Continue to cook for about 5-8 minutes. As a result, the fruit will break down and the mixture will thicken into a beautiful, jam-like consistency. Finally, remove the filling from the heat and set it aside to cool slightly while you prepare the crumble.

Part 2: Make the Oat Crumble and Assemble the Bars

4. Step 4: Combine the Dry Ingredients. In a large mixing bowl, whisk together the all-purpose flour, rolled oats, packed light brown sugar, baking powder, ground ginger (if using), and salt. Whisking ensures everything is evenly distributed and breaks up any large lumps of brown sugar. Therefore, your crumble will have a consistent texture.
5. Step 5: Cut in the Cold Butter. Add the cold, cubed butter to the dry ingredients. Using a pastry blender or your fingertips, cut the butter into the flour mixture. Continue this process until the mixture resembles coarse, wet sand with some pea-sized butter clumps remaining. Do not overmix; these small butter pieces are essential for creating a tender crust and crumbly topping.
6. Step 6: Form the Base Layer. Take approximately two-thirds of the crumble mixture (about 4 heaping cups) and press it firmly and evenly into the bottom of your prepared pan. Use the bottom of a flat measuring cup or your hands to create a compact, even layer. This layer will form the sturdy base for your delicious strawberry rhubarb bars.
7. Step 7: Add the Filling and Topping. Carefully pour the slightly cooled strawberry rhubarb filling over the crumble base. Then, spread it into an even layer with an offset spatula or the back of a spoon. Sprinkle the remaining one-third of the crumble mixture evenly over the top of the fruit filling. Don’t press it down; let it remain loose for a lovely crumbly texture.

Part 3: Bake, Cool, and Slice

8. Step 8: Bake the Bars to Perfection. Place the pan in the preheated oven. Bake for 40-50 minutes. The bars are done when the fruit filling is bubbly around the edges and the crumble topping is a beautiful golden brown. Moreover, the center should look set.
9. Step 9: Cool Completely (This is Critical!). This step is non-negotiable for perfectly set bars. First, remove the pan from the oven and place it on a wire cooling rack. Let the bars cool completely in the pan to room temperature, which will take at least 2-3 hours. For best results and the cleanest cuts, you can then chill them in the refrigerator for another hour before slicing.
10. Step 10: Slice and Serve. Once fully cooled and set, use the parchment paper handles to lift the entire slab out of the pan. Place it on a cutting board and use a sharp knife to slice into bars of your desired size (16-24 bars is standard). Finally, they are ready to serve and enjoy!

Baking Tips, Variations & Substitutions

Pro Tips for Perfect Strawberry Rhubarb Crumb Bars

• Use Cold Butter. Always. For a tender and crumbly texture, your butter must be cold, straight from the fridge. Cold butter creates small pockets of steam as it bakes, which results in a lighter, more delicate crumb structure. Avoid using softened or melted butter for the crumble mixture.
• Don’t Overcook the Filling. The fruit filling only needs to be cooked on the stovetop until it begins to thicken. It will continue to cook and set further in the oven. Overcooking it on the stovetop can result in a mushy, dull-colored filling.
• Patience is Key for Cooling. We can’t stress this enough! Cutting into the bars while they are still warm is tempting, but it will result in a runny mess. Allowing them to cool completely gives the cornstarch-thickened filling time to set properly, ensuring clean, beautiful slices.
• Pack the Base Firmly. When pressing the bottom layer of crumble into the pan, make sure it’s compact. This creates a solid foundation that can hold the jammy filling without becoming soggy.

Easy Variations You Can Try

• Get Creative with Spices. While ground ginger is a wonderful complement, feel free to experiment. A teaspoon of ground cinnamon or a pinch of cardamom in the crumble mixture can add a lovely warmth and complexity.
• Add a Nutty Crunch: Mix 1/2 cup of chopped walnuts or pecans into the topping portion of the crumble mixture before sprinkling it over the fruit for added texture and nutty flavor.
• Try Other Fruits: While strawberry and rhubarb are a classic pair, you can substitute other fruits. Try a mix of raspberries and rhubarb, or use all berries for a different flavor profile.
• Make them Gluten-Free: To make this recipe gluten-free, substitute the all-purpose flour with a high-quality 1-to-1 gluten-free baking flour blend (one that contains xanthan gum). Additionally, ensure you use certified gluten-free rolled oats to avoid any cross-contamination.

How to Serve & Store Your Strawberry Rhubarb Crumb Bars

These Strawberry Rhubarb Crumb Bars are delightful on their own, perhaps with a dusting of powdered sugar. However, for an extra special treat, serve them slightly warmed with a scoop of vanilla bean ice cream or a dollop of fresh whipped cream. The contrast between the warm, fruity bar and the cool, creamy topping is absolutely divine.

To store, place the cut bars in a single layer in an airtight container. They can be kept at room temperature for up to 2 days, though the crumble will soften slightly over time. For longer freshness, store them in the refrigerator for up to 5 days. You can serve them chilled directly from the fridge or let them sit at room temperature for 15-20 minutes before enjoying. For another family-friendly dessert, try our reader-favorite Moist Banana Bread recipe!

Watch: How to Make It

Frequently Asked Questions