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Blueberry Crumble Bars

Blueberry Crumble Bars are buttery, sweet and loaded with juicy, fresh blueberries. These are the perfect summery blueberry dessert!

Love blueberries? Make sure to try my super easy Blueberry Cobbler recipe!

This post was originally published in 2016. The photos and tips have been updated in 2021. The recipe remains the same!

These Blueberry Crumble Bars Are Going To Be Your Favorite Summer Dessert Recipe!

If you love a good fruit dessert for the summer, and want to do something a little different than a cobbler or fruit salad, these Blueberry Crumble Bars are exactly what you’re looking for! These sweet bars are always the hit of every BBQ, party, or event, and I’m constantly being asked for the recipe!

The Crumble Topping Is Also the Crust!

What makes these blueberry bars so easy is that the crumb topping is also the crust! This makes the prep step extra easy! The crumb topping is a buttery streusel-style layer that you simply press half of into the bottom of the pan and then top with the remaining mixture.

It’s sweet and rich, with the perfect texture thanks to the rolled oats!

Crumble topping on blueberry bars close up


  • all purpose flour
  • old fashioned oats (rolled oats)
  • light brown sugar
  • kosher salt
  • butter
  • granulated sugar
  • cornstarch
  • blueberries
  • lemon juice
Fresh blueberries coated in sugar for Blueberry Crumble Bars

Tips When Making Blueberry Crumble Bars:

What I love most about this recipe is that it’s very easy. Here are a few tips to make the process super simple!

  1. I use my blender to combine the ingredients, but you can easily use a food processor. Or if elbow grease and a pastry cutter is your favorite method use “Quick Oats” in place of the old fashioned.
  2. Coating the fresh blueberries in sugar and cornstarch makes a sweet filling and also thickens it up thanks to the cornstarch!
  3. The blueberries will begin to bubble as they bake. This means the bars are just about done! Don’t over-bake the bars, as this will make the crust and the topping too hard to cut successfully. Trust me on this!
Bars with a shortbread crust, blueberry filling, and crumb topping cut and stacked showing the filling

Can You Use Frozen Blueberries?

Yes you absolutely can, just thaw out the blueberries and pat them dry! This is a great recipe to make during blueberry season when they are the ripest, but frozen blueberries are a great alternate! I always buy or pick extra blueberries during peak season so I can freeze and enjoy them all year long!

How Do You Store These Blueberry Bars?

I recommend storing these bars in the refrigerator, airtight, for up to 3 days. You CAN store them at room temperature, but I would only advise doing that for 1 overnight. The moisture in the blueberries will cause the topping to get a little soggy, and the refrigeration helps slow this process!

Can You Freeze Blueberry Crumble Bars?

Yes, absolutely! These bars freeze very well! Allow them to thaw in the refrigerator, and you can enjoy them chilled, or at room temperature!

Blueberry Crumble Bars cut into squares from above

Looking For More Blueberry Recipes? Try These:


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Blueberry Crumb Bars cut and stacked

Blueberry Crumble Bars

  • Author: Cookies & Cups
  • Prep Time: 20 minutes
  • Chill Time: 30 minutes
  • Cook Time: 40 minutes
  • Total Time: 1 hour 30 minutes
  • Yield: serves 20 1x
  • Category: Fruit
  • Method: Oven
  • Cuisine: Dessert


Sweet  Blueberry Crumble Bars are going to be the hit of your next BBQ!



Crumble Mixture:

  • 1 1/2 cups all purpose flour
  • 1 1/2 cups old fashioned oats
  • 3/4 cups light brown sugar
  • 1/2 teaspoon kosher salt
  • 1 cup cold butter, cubed


  • 1/2 cup granulated sugar
  • 3 tablespoons cornstarch
  • 2 1/2 cups blueberries
  • 1 tablespoon lemon juice


  1. Line a 9×9 pan with parchment paper and coat with nonstick spray. Set aside.
  2. Crumble Mixture: In your blender or food processor pulse together flour, oats, brown sugar and salt until combined. Add in the cold butter and pulse until combined and resembles very coarse sand.
  3. Divide the mixture in half and press half into the bottom of the prepared pan to form the crust. Set aside.
  4. Filling: In a large bowl whisk together the granulated sugar and cornstarch. Add in the blueberries and coat in the sugar mixture. Add in the lemon juice and stir to combine.
  5. Spread the blueberries on top of the crust.
  6. Finally spread the remaining crust mixture on top of the blueberries and press lightly.
  7. Refrigerate the pan for 30 minutes.
  8. Preheat the oven to 350°F and bake for 35-40 minutes until the fruit starts to bubble.


Don’t over-bake, as the crust will become too hard.
Chilling the bars before baking is not optional!

Store airtight in the refrigerator for up to 3 days.

Keywords: cookies and cups, blueberry dessert, blueberry crumble, bar desserts, summer desserts

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45 comments on “Blueberry Crumble Bars”

  1. Wow. I made this crumble bar with blueberries and raspberries and it was fantastic. The whole family loved it. The crumble was beautiful and buttery with an almost caramely flavour and the berries brought a nice tangy contrast. With ice cream it is absolutely irresistible. Would highly recommend!

  2. Me again lol. So they are cooled and they taste amazing!!! My crust just wasn’t crumbly. When I would pulse the blender everything mixed we except for the butter it stayed on top in big chunky pieces. I took it out and did it by hand but then it was Doughy instead of crumbly?? Not sure but the flavor is amazing!

  3. Not Sure what happened but I used my blender and I wasn’t able to get that Sandy feel it turned out looking more like dough I did pulse it. 🙁 it’s still cooling but definitely doesn’t look crumbly it still looks like it’s possibly under cooked? I baked it for 40 minutes

  4. I made these yesterday and OMG!! They are amazing!!! Of all the online recipes I’ve ever made, I’ve never written a review (and that’s a lot of recipes) but I had to come back and let everybody know that these are SO good! My family gobbled them up. I have lots of blueberries in my yard so I’m always looking for new ways to cook with them. I doubled the recipe and used a 9×13 glass pan with parchment paper. I used half vegan butter and half coconut oil instead of butter, otherwise I followed it exactly. I baked them an extra 10-15 minutes until the edges were golden and the fruit was bubbly.

    They were GREAT out of the oven, they did fall apart but it became this delicious hot mess that would have tasted fantastic with ice cream. I refrigerated them and the next day they are EVEN BETTER! They are much easier to cut into bars and they hold up beautifully. They are very rich so next time I would add less sugar to the berries and the crust. I would say to the person who thought they were greasy, maybe you didn’t refrigerate them before baking, or your measurements were off, or maybe you melted the butter. (I just put all the crust ingredients in a bowl and dug in with both hands). But it’s a shame you had to throw them away.

    THANK YOU for this recipe, it’s a keeper and a crowd-pleaser for sure! And such a TASTY way to get through all those blueberries!!

    1. aww thank you so so much for the review! I am so glad you liked them! I make them all the time and have played around with less sugar, and it works well! It’s one of my friend’s most favorite recipes on my site!

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