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:



Blueberry Crumble Bars

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

Want To Save This Recipe?




PIN for later:

Blueberry Crumble Bars Pinterest Image

Hi! I’m Shelly and I’m an addict. Of the buttercream sort. I started this site a few years ago as a way to justify my sugary, buttery obsession with desserts. It has worked out well for me so far, because as it turns out you guys all love sugary, buttery desserts too! It feels good to know you're not alone, doesn’t it?

You might also like...

Share Your Comments

Want to share a photo of what you’ve made? Be sure to register or log in and then click the camera icon located at the bottom of the comment form.

Recipe rating
Oldest Most Voted
Inline Feedbacks
View all comments
Nov 27, 2019 5:28 am

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!

Jul 8, 2019 1:02 am

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!

Jul 7, 2019 10:31 pm

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

Jul 7, 2019 8:22 pm

I only have 8 by 8. You think it’ll come out okay?

Jul 20, 2017 5:22 pm

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… Read more »

Apr 9, 2017 11:19 pm

Have you tried making it with less sugar??

Wanda Firmingham
Nov 23, 2016 4:37 am

Does it have to be kosher salt or can I use regular table salt??

Nov 27, 2016 2:48 am
Reply to  Shelly

What other fruits can I use?! Pls mention them apples?! Strawberries?!

Sep 15, 2016 7:19 pm

I’m wondering if I dare mix this up tonight and leave it in the fridge to bake in the morning. I’m using frozen wild blueberries and am a little worried that they will shed some water or juice as they defrost. and have a negative effect on the crust.Though, having said that, I suppose I could just defrost them before adding them and let them drain first. Your thoughts? Thanks!

Aug 20, 2016 5:32 am


Aug 18, 2016 11:10 am

Is it salted or unsalted butter that’s used in this recipe?

Aug 17, 2016 10:22 am

Hi, i wanna try this! Ive been following you on Instagram. Can I use the canned blueberries? Sadly, Fresh ones are not available in our country. Thank you.

Aug 1, 2020 12:55 pm
Reply to  Shelly

Can I use frozen blueberries if I thaw them?

Aug 4, 2020 2:11 pm
Reply to  Shelly


I have definitely not done all the things I wanted to this summer! It has flown by. These bars look super yummy!

Amy Iversen
Aug 4, 2016 3:30 pm

I made this in a 9×9 pan….the crust was a little thick….did I get the pan size right?

Aug 2, 2016 2:28 pm

Made these and it’s like blueberry crumble pie in cookie form. Everyone loved these (even the kids) I did refrigerate mine to help keep the blueberries from “running”. This recipe is a keeper!

Aug 1, 2016 12:27 am

The top and bottom seemed greasy like there’s too much butter in the oat mixture. It didn’t set up well either. I tossed it. Is it really one cup of butter and not one cube?

Shelly Hi! I’m Shelly and I’m an addict. Of the buttercream sort. I started this site a few years ago as a way to justify my sugary, buttery obsession with desserts. It has worked out well for me so far, because as it turns out you guys all love sugary, buttery desserts too! It feels good to know you're not alone, doesn’t it?

Tips for Baking Success!

Cookies and Cups Newsletter Get 5 Baking Secrets That Will Change Your Life!

Delivered Straight to Your Inbox, For Free:

Recipes You’ll Love

This site participates in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means to earn a small fee by linking to and affiliated sites.

Ad Blocker Detected!

Advertisements fund this website. Please disable your adblocking software or whitelist our website.
Thank You!