These strawberry rhubarb bars have a gooey sweet-tart filling made with fresh strawberries and rhubarb topped with a buttery oat crumble. I use the same crumble recipe for the topping and the crust, so it’s extra easy!

With fresh fruit filling baked under crumbly oats, these crumb bars are a bit like an apple crisp made with juicy summer strawberries and rhubarb. Even better, you can take these on the go!

A stack of three strawberry rhubarb bars on a white plate next to a fresh strawberry.

Irresistible Strawberry Rhubarb Crumb Bars

I’ll come right out and say it: I’m not the biggest fan of rhubarb. But my parents are, and every year when we were kids they grew huge rhubarb plants in the garden. When my mom visited earlier this summer, I made her these strawberry rhubarb bars and she absolutely loved them. I think these bars would be just as delicious made with strawberries only, if you’re also on the fence. But in the meantime, rhubarb lovers, this one’s for you!

Why You’ll Love These Strawberry Rhubarb Bars

One crumble, two ways. The easy crust recipe does double duty as a crumble topping, with a thick, chewy layer of ripe strawberries and rhubarb between the crunchy oat crust and crumble. It saves me the extra work of making a separate crust!
Quick. These strawberry rhubarb crumb bars need just 30 minutes of hands-on prep before they’re ready for your oven. It’s an easy dessert that’s perfect for rhubarb season.
Fresh fruit filling. Sweet strawberries and tart rhubarb are a classic combination. This recipe has just enough rhubarb in the mix, while the fresh strawberry flavors shine through.

A strawberry rhubarb bar with a bite missing on a white plate.

Key Ingredient Notes

These strawberry rhubarb bars keep it super simple in the ingredient department. I’ve included some notes on the key ingredients here. Be sure to scroll to the printable recipe card after the post for the full recipe details.

Oats – The best oats for the crust/topping are old-fashioned (rolled) oats.
Flour – When measuring the flour, spoon the flour into the measuring cup rather than scooping it directly from the bag. Level off the top with a knife, and you’ll have the perfect cup of flour that isn’t overmeasured.
Sugar – I use brown sugar but granulated sugar works, too.
Cinnamon – Or nutmeg.
Rhubarb – If you’re buying fresh rhubarb from the store, look for stalks that are firm and crisp. Colors range from bright red to speckled pink and even green, so it’s best not to judge rhubarb’s ripeness by color alone. Discard the leaves before you dice up the stalks.
Lemon Juice – Freshly squeezed is best, but the bottled kind works in a pinch.
Cornstarch – Or flour, to thicken the fruit filling.

Fresh vs. Frozen Rhubarb

Frozen rhubarb can be used instead of fresh rhubarb in these fruit bars. It’s best to thaw frozen rhubarb in the fridge overnight and drain it before you use it. I also recommend increasing the cornstarch in the recipe by 1-2 tablespoons, to compensate for the excess liquid.

Ingredients for strawberry rhubarb bars with text labels overlaying each ingredient.

How to Make Strawberry Rhubarb Bars

I love that the deliciously buttery crust doubles as a crumble topping. It cuts down on prep time and makes an already easy dessert bar recipe even easier! Follow these steps and refer to the recipe card at the end of the post for printable instructions.

Prepare the crumble. Combine the ingredients for the oat crumble and cut in cubed butter and vanilla until the mixture resembles cookie dough. Set aside some of the mixture for the topping.
Make the crust. Press the rest of the oat mixture into the bottom of a lined 9×13” baking pan. Par-bake the crust at 350ºF for 10-12 minutes.
Make the filling. Toss the diced strawberries and rhubarb with sugar and let that sit and macerate for 5-10 minutes. Afterward, drain the liquid, and toss again, this time with cornstarch, lemon juice, and the rest of the sugar.

The mixture for the crumble topping and crust in a glass bowl. — Prepare the oat crumble mixture.

Diced strawberries and rhubarb combined in a glass bowl with a wooden spoon. — Prepare the oat crumble mixture.

Assemble. Spread the fruit filling over the baked crust. Sprinkle over the last of the oat crumble from earlier. I like to leave some gaps so the bright red filling can peak out, a bit like a cobbler.
Bake. Return the bars to the 350ºF oven to bake for 40-45 minutes. Let the bars cool and refrigerate them for an hour or so before cutting them into squares.

Strawberry rhubarb layer added to the crust in a lined baking pan. — Layer the filling over the crust.

Assembled strawberry rhubarb crumb bars in a lined baking pan. — Layer the filling over the crust.

Julianne’s Tips

Line the pan. Greased parchment paper is the best choice for these bars as the fruit mixture becomes very sticky and jam-like after baking. The bars stick to foil, so it’s best to grease your 9×13” pan extra well if you don’t have parchment.
Use the right oats. Make sure to use rolled oats (old-fashioned oats) for this recipe. Quick oats will soften too much when baked, and steel-cut oats won’t soften enough.
How to tell when the bars are done. Your strawberry rhubarb crumb bars are ready to come out when the filling thickens up and starts to bubble. The crumble should also be a light golden brown.
Let the bars cool before cutting. These bars are super gooey when they’re fresh out of the oven. Let the baked strawberry bars cool completely to room temperature, and then chill them in the fridge before you slice them. This way the filling won’t ooze out everywhere.

Overhead close up view of freshly cut strawberry rhubarb bars garnished with two fresh strawberry slices.

Serving Suggestions

These strawberry rhubarb bars taste great cold, at room temperature, or you can enjoy them warm. When my mom was over, we topped the warm bars with a scoop of vanilla ice cream and had them with a cup of tea. They’d also go great with strawberry ice cream, or a dollop of homemade whipped cream. If you’re a dessert-for-breakfast person, serve these bars alongside savory brunch favorites like quiche, bacon, and crispy potatoes.

Assorted strawberry rhubarb bars stacked on a large platter.

How to Store

Store leftover strawberry rhubarb bars in an airtight container in the fridge for up to 5 days. Unfortunately, these bars don’t freeze well since there’s a lot of moisture in the fruit that makes them mushy once they’re thawed.

Strawberry Rhubarb Bars