Strawberry Rhubarb Crumb Bars Recipe for a Sweet Tart Spring Dessert

Name: Strawberry Rhubarb Crumb Bars
Prep time: 1 h 20 min
Cook time: 45 min
Total time: 1 h 5 min
Cuisine: American
Ingredients: 1 ½ cups all purpose flour; ½ teaspoon baking soda; ½ teaspoon kosher salt; 1 ½ cups old fashioned rolled oats (not quick or steel cut); ¾ cup packed brown sugar; ½ cup granulated sugar; ¾ cup cold unsalted butter, cut into small cubes; 1 teaspoon vanilla extract; 2 cups fresh strawberries, diced; 2 cups fresh or frozen rhubarb, diced (if frozen, thaw and drain first); 1 tablespoon fresh lemon juice; ½ cup granulated sugar; 2 tablespoons cornstarch

By:

Ruby Bennett

Published:

June 11, 2026

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Strawberry Rhubarb Bars Ingredients

Let me tell you, these strawberry rhubarb crumb bars are my all time favorite fruit bar. The balance of sweet strawberries and tart rhubarb with that buttery oat crumble is just irresistible! Here is what you will need for this crowd pleasing spring dessert.

For the Crumb Topping and Crust:

1 ½ cups all purpose flour
½ teaspoon baking soda
½ teaspoon kosher salt
1 ½ cups old fashioned rolled oats (not quick or steel cut)
¾ cup packed brown sugar
½ cup granulated sugar
¾ cup cold unsalted butter, cut into small cubes
1 teaspoon vanilla extract

For the Fruit Filling:

2 cups fresh strawberries, diced
2 cups fresh or frozen rhubarb, diced (if frozen, thaw and drain first)
1 tablespoon fresh lemon juice
½ cup granulated sugar
2 tablespoons cornstarch

These strawberry rhubarb crumb bars use simple pantry staples and fresh seasonal fruit. The combination of strawberries and rhubarb is a classic for a reason. It is just perfect for spring and summer baking!

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How to Make Strawberry Rhubarb Bars

Making these strawberry rhubarb crumb bars is easier than you think. You get a buttery shortbread like crust, a gooey fruit filling, and a crumbly oat topping all in one pan. The best part? You do not need to prebake the crust. It all bakes together in one go.

Preheat your oven to 350°F. Butter a 9×9 inch baking dish and line it with parchment paper. This makes it super easy to lift the bars out later for clean cutting. If you want to skip the parchment, just butter the dish well.

Instructions

Step 1: Make the Crumb Layer

In a large mixing bowl, whisk together the flour, baking soda, and salt. Add the oats, brown sugar, and granulated sugar. Whisk to blend everything evenly. In a small bowl or measuring cup, whisk the vanilla extract into the melted butter. Pour the butter mixture over the oat mixture and stir with a fork until it is evenly moistened. The mixture should look like coarse crumbs.

Step 2: Press the Base

Press about two thirds of the crumb mixture firmly into the bottom of your prepared baking dish. Set the remaining one third aside for the top. This forms your sturdy bottom crust.

Step 3: Make the Fruit Filling

In a separate mixing bowl, toss the diced strawberries and rhubarb with the fresh lemon juice. In a small bowl, whisk together the sugar and cornstarch. Pour the sugar mixture over the fruit and toss gently until the fruit is evenly coated. The cornstarch helps thicken the juices as they bake so you do not get a runny filling.

Step 4: Assemble and Bake

Pour the fruit mixture over the bottom crumb layer and spread it out evenly. Sprinkle the remaining crumb mixture on top. Bake for 45 to 50 minutes, until the top is golden brown and the fruit filling is bubbling around the edges. Let the bars cool completely on a wire rack before cutting. The hot filling can burn your mouth, so patience is key!

One important tip: Let the bars cool completely before slicing. The filling needs time to set, and cutting too early will make a messy, runny situation. Trust me on this!

Can I Use Frozen Fruit in This Recipe?

Yes, you can absolutely use frozen fruit in these strawberry rhubarb crumb bars. Frozen rhubarb and frozen strawberries both work well. The main thing to keep in mind is that frozen fruit has more moisture than fresh.

If you are using frozen rhubarb, thaw it first and drain off as much excess liquid as you can. Pat it dry with paper towels if you want to be extra careful. You do not need to thaw frozen strawberries, but if you do, drain them too. Too much extra liquid in the filling can make the bars soggy, and nobody wants that. The fresh flavor will be slightly less intense than with peak season fruit, but these bars will still be delicious.

How to Store Strawberry Rhubarb Crumble

Storing these strawberry rhubarb crumb bars is simple. They keep best in an airtight container at room temperature on your counter. They will stay fresh for up to 3 days. I do not recommend storing them in the refrigerator because the cold air will make the crumb topping mushy. That crunchy oat crumble is one of the best parts!

If you need to keep them longer, you can freeze the baked and cooled bars. Wrap each bar tightly in plastic wrap, then place them in a freezer safe container or bag. They will keep for up to 3 months. When you want one, just pull it out and let it thaw at room temperature for about 30 minutes. They taste almost as good as fresh!

Tips for the Best Strawberry Rhubarb Crisp

After making these strawberry rhubarb crumb bars more times than I can count, I have gathered a few tips that really make a difference. Here are my best suggestions.

Use Old Fashioned Oats

You must use old fashioned rolled oats for these bars. Quick oats and instant oats will turn into mush. Steel cut oats are too tough and will not soften properly. Old fashioned oats give you that perfect chewy texture in the crumb topping.

Let Them Cool Completely

I know it is hard to wait, but letting the bars cool completely on a wire rack is non negotiable. The hot fruit filling can burn your mouth, and cutting too early makes a mess. Give them a full hour or more. They are worth the wait.

Serve with Vanilla Ice Cream

A scoop of vanilla ice cream or a dollop of whipped cream is the classic pairing. The cold creaminess against the warm fruit and crunchy crumble is pure magic. It is a perfect spring dessert.

Customize the Crumb Topping

You can easily add your own twist to these strawberry rhubarb crumb bars. Try adding a pinch of cinnamon or nutmeg to the sugar mixture for a warm spice note. A little fresh lemon zest in the fruit filling brightens everything up. For extra crunch, stir in some chopped almonds or walnuts into the reserved crumb topping. If you are making them dairy free, swap the butter for coconut oil. Gluten free bakers can use a 1 to 1 gluten free all purpose flour blend or almond flour. The options are endless!

Frequently Asked Questions

How do you make strawberry rhubarb crumb bars?

Start with a base layer of butter, flour, sugar, and oats pressed into a baking pan. Add a layer of fresh or thawed frozen rhubarb and strawberries mixed with sugar and cornstarch. Top with the remaining crumb mixture and bake until golden and bubbly, about 40 to 45 minutes at 375°F. Cool completely before slicing for clean bars.

Can I use frozen rhubarb for crumb bars?

Yes, frozen rhubarb works well. Thaw it first, drain any excess liquid, and pat dry with paper towels to avoid excess moisture. You do not need to thaw frozen strawberries if using, but rhubarb releases more water so draining is key.

What is the best way to store strawberry rhubarb bars?

Store in an airtight container at room temperature for up to 2 days, or in the refrigerator for up to 5 days. For longer storage, freeze in a sealed container or freezer bag for up to 3 months.

Do you need to prebake the crust for rhubarb crumb bars?

No, prebaking is not necessary. The crumb base is pressed into the pan and bakes together with the fruit filling. This keeps the crust tender and prevents it from becoming too hard.

Can you freeze strawberry rhubarb crumb bars?

Yes, these bars freeze well. Wrap individual bars in plastic wrap, then place in a freezer safe container or bag. Thaw at room temperature for about 30 minutes before serving. They keep for up to 3 months.

What type of oats should I use for crumb bars?

Use old fashioned rolled oats, not quick or instant oats. Old fashioned oats provide a chewy texture and hold up better during baking. Steel cut oats are too tough and will not soften properly in the crumb topping.

Strawberry Rhubarb Crumb Bars Recipe for a Sweet Tart Spring Dessert

Strawberry Rhubarb Bars Ingredients