Gimme Some Oven

Blueberry Crumble Bars

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This Blueberry Crumble Bars recipe is quick and easy to make, and filled with the most irresistible sweet blueberry filling. Perfect for fresh berries in the summertime, or frozen berries year-round.

Easy Blueberry Crumble Bars Recipe

After six months of hosting back-to-back visitors here in our flat in Barcelona, we just picked up our final set of visitors for the season at the airport yesterday — my aunt, uncle and cousins from Kansas.

They came over to Europe to visit my cousin, Michael, who was studying abroad in Paris this summer. And after a whirlwind trip in France, flew down yesterday to Barcelona to conclude their trip in Spain, where we’ve already had a fun time introducing them to Gaudí and vermouth and tapas galore. And since they’ve been eating out non-stop the past few weeks, we figured they might be ready for an easy night in. So tonight, Barc and I are planning to prepare a big cheeseboard with our favorite Spanish cheeses, hams, nuts, olives, breads, jams and paraguayos, an enormous salad (to balance out all of those carby tapas we’ve been eating), a tasting of our favorite vermouths (because, Spain). And for dessert — these blueberry crumble bars. Because, summer. ♡

As some of you have seen on Instagram, I’ve been tinkering around this week with recipes for how to make the perfect blueberry bars. And after many berry-licious batches, I’ve settled on a recipe that Barclay and I both love.  It’s made with a buttery oatmeal crisp, which is pressed into a bar on the bottom layer and crumbled on top. It’s filled with a luscious blueberry filling, made with fresh blueberries this time of year (or frozen year-round). It’s mostly just sweetened with berries, instead of cups and cups of extra sugar. And it is absolutely delightful.

Just the right thing for a simple, cozy, summertime meal around the table with family, if I do say so myself. And, if an extra scoop of ice cream happens to appear in the serving bowls tonight too, I wouldn’t complain about that either. ;)

Fresh blueberries

Blueberry Filling Ingredients:

Alright, first things first, let’s talk about the most irresistible part of this recipe — that sweet, summery, ultra-satisfying blueberry filling. It’s made with just four simple ingredients:

  • Blueberries: fresh if they are in season, or frozen the rest of the year
  • Lemon juice: to add a little zest and bring out the flavors of these blueberries
  • Brown sugar: as needed, to sweeten
  • Cornstarch: to thicken (very important, or else you’ll be eating these with a spoon, which isn’t the worst thing in the world ;))

How to make blueberry filling

How To Make The Blueberry Filling:

To make the blueberry filling, simply:

  1. Combine all of the ingredients together in a large saucepan.
  2. Heat until the mixture comes to a simmer.
  3. Then simmer for about 10 minutes, stirring and mashing a few of the blueberries occasionally. (I liked leaving some blueberries whole, but the texture is up to you.)

Then voila, it’s ready to go! Super simple.

How to make oatmeal crumble for fruit crumble bars

Oatmeal Crumble Ingredients:

Meanwhile, as your berries are cooking, let’s work on the oatmeal crumble. To make it, you will need:

  • Old-fashioned oats: Not quick or steel-cut. Old-fashioned oats are the way to go here.
  • Flour: All-purpose or white whole wheat.
  • Brown sugar: Just 1/2 cup, not too much.
  • Cinnamon and salt: For seasoning.
  • Melted butter: Because…dessert. If you’re avoiding butter for whatever reason, these bars can also be made with coconut oil. But I much prefer the flavor of butter here.

How to make the oatmeal crumble for blueberry bars

How To Make The Oatmeal Crumble:

To make the oatmeal crumble, simply:

  1. Whisk all of your dry ingredients together. Oats, flour, brown sugar, cinnamon, salt.
  2. Add in the melted butter. Yummm.
  3. Then give everything a stir.  Until it’s completely combined.

Blueberry Bars Recipe

How To Assemble Blueberry Crumble Bars:

Then, to assemble the bars…

  1. Press half of the crumble mixture into your baking dish. I used an 8×8-inch baking dish, lined with parchment for easier removal. And I recommend really giving this bottom layer a good press down, so that it forms a nice and even and compact base for your bars.
  2. Pour the blueberry filling on top. And spread it around evenly with a spoon.
  3. Add the remaining crumble on top. Crumbling it up with your fingers, and sprinkling it evenly over the top of the blueberry layer.
  4. Pop it in the oven. And bake at 350°F for about 30 minutes, or until the berries are nice and bubbly and the topping is crispy.
  5. And chill. Then remove and transfer the pan to a cooling rack until the bars reach room temp. Cover. And refrigerate for a few hours until the bars are completely chilled, which will make them easier to slice and hold.

Easy Blueberry Bars Recipe

Then once the bars are nice and chilly, slice them up…

The BEST Blueberry Crumble Bars Recipe -- made with a buttery oatmeal crisp and fresh blueberry filling

…and serve! ♡

Blueberry Bars Recipe with Oatmeal Crumble

As I mentioned, these are absolutely delicious when served with a side of vanilla ice cream in the summertime. But they’re also perfectly lovely on their own. I have a feeling you are going to love them.

Enjoy, everyone!

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Blueberry Bars

5 Stars 4 Stars 3 Stars 2 Stars 1 Star 5 from 11 reviews
  • Prep Time: 20 minutes
  • Cook Time: 30 minutes
  • Total Time: 50 minutes
  • Yield: 12 -16 servings 1x


This Blueberry Crumble Bars recipe is quick and easy to make, and filled with the most irresistible sweet blueberry filling.  Perfect for fresh berries in the summertime, or frozen berries year-round.


  • 1 pound (about 4 cups) fresh or frozen blueberries
  • ¼ cup brown sugar, tightly-packed
  • ¼ cup lemon juice
  • 1 ½ tablespoons cornstarch
  • 2 ¼ cups old-fashioned oats
  • 1 ½ cups all-purpose flour
  • ½ cup brown sugar, packed
  • ½ teaspoon ground cinnamon
  • ½ teaspoon salt
  • 1 cup (2 sticks) melted butter


  1. Preheat oven to 350°F.  Line an 8×8- or 9×9-inch square baking dish with parchment paper; set aside.
  2. In a large saucepan, stir together the blueberries, brown sugar, lemon juice and cornstarch until combined.  Heat over medium heat until the blueberries reach a simmer, stirring occasionally.  Then reduce heat to medium-low and simmer for 10 minutes, stirring and mashing a few of the blueberries occasionally, until the mixture is thickened.  Remove from heat and set aside.
  3. Meanwhile as the berries are cooking, whisk together the oats, flour, brown sugar, cinnamon and salt until combined.  Drizzle the melted butter evenly over the mixture, then stir until completely combined.
  4. Transfer half of the filling to the prepared pan, and press it evenly into the bottom of the pan to form the bottom layer of the bars.  Pour the blueberry mixture on top, and spread it around evenly.  Then use your fingers to crumble and evenly sprinkle the remaining oatmeal mixture on top of the blueberry layer.
  5. Bake for 30-35 minutes, or until the blueberries are bubbling around the edges.  Transfer to a cooling rack and cool until the bars reach room temperature.  Then cover and refrigerate until completely chilled.
  6. Cut and serve chilled.  Or store in the refrigerator for up to 4 days.

Blueberry Crumble Bars Recipe from Gimme Some Oven

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24 comments on “Blueberry Crumble Bars”

  1. I’m going to adapt this with some great peaches we have right now. I’ll let you know…

  2. OMG! This sounds so good!! I have got to try this! (I’ll be using organic for most of the ingredients). Thanks for sharing.

  3. MaMa Mia!! I can’t wait to try these, they look amazing!!! Just pulling a zucchini cake out of the oven, but your blueberry bars will be next on my list!

    Yes, I would love info on the cheeseboard you’re planning, that too sounds fantastic.

    Thanks for sharing:)

  4. Can Almond Flour be substituted for someone suffering from Celiacs Disease and can’t eat wheat flour?

    • I actually tried a batch with almond flour and it was delicious! It definitely forms more of a thinner crisp on the top and bottom, vs a more bar-like consistency. But it’s delicious!

  5. Oh these sound delish! I’m so glad you didn’t add so much sugar. Most recipes call for way too much sugar and then i have to try and guess at what would be good but not too sweet. Thanks for sharing this recipe. I’m glad you got to spend time with family. I know you have been missing them!

  6. Safe to assume the oats are combined with the flour mixture?

  7. Love fruit bars…cannot wait to make these! And serving with a scoop of vanilla ice cream is a must :)

  8. These Blueberry Crumble Bars look so scrumptious that I have to make them. And serving them with ice cream or even just mascarpone cheese must be fantastic. I’m going to save this recipe. Thank you!


  9. This is in the oven right now! I don’t know if I can wait long enough to cool and chill! Lol!!!

  10. Hi, I made these yesterday and they are AMAZING!!! I chopped up some toasted pecans and added it to the crumb topping, pure perfection. I knew I couldn’t keep these in the house, so I took some to a friend and froze the rest. This one is a keeper for sure!!

    Thank you for sharing

  11. Made these last night with my daughter, OMG! They’re delicious and didn’t last long enough to have with ice cream! Will definitely make them again, thanks for the recipe!

  12. These were just excellent. Used the recipe as written (including butter) with fresh blue berries. This is the best blueberry bake I’ve ever tasted…………….or at least at the top. It is better however, when eaten the day it’s made.

  13. I made this and it’s absolutely delicious!!! One of the best treats ever! I have made many of your recipes and they’re all wonderful. Thank you for all of your hard work and sharing with us.

  14. I made these for my family and they absolutely DEVOURED them! We ate them for breakfast and I wish I had made a double batch. Thanks for the great recipe!

  15. I just made these and we had to try them before they cooled. Yummy! They are in the frig now. Can’t wait to try cooled and with ice cream. I actually remembered to take pictures this time, but where do you post them? Twitter? Facebook? I’ve never posted a picture before.

  16. Hi Ali, I have made these several times and they are ALWAYS a hit. I would like to make them for a party this weekend, but I have someone who is GF/DF. I have GF flour and it always works perfectly, but what can I use in place of the butter? Thank you!

  17. I’ve made these before and wow were they delicious!! I’ve got all the ingredients to make them now, EXCEPT for all-purpose flour, which is impossible to get in the stores right now…. do you think “oat flour” would work as a substitute?

  18. Would be even better if you would also put metric units as well, so that we would not need to convert :)

  19. I just made these with half the amount of blue berries needed and it turned out great. I substituted lemon curd for the other half as thats what we had on hand and oh my word…amazing.

    We loved how it married and turned out.

    I added a layer of lemon curd then a layer before the blueberries then followed the rest of the directions.

    :) <3

  20. This recipe is ridiculous! Even with not super sweet blueberries, the flavors, texture and presentation is amazing. I will be posting and tagging This recipe you on Instagram this week. I could have eaten the entire bowl of crumble by itself. BTW – your lemon artichoke soup is now a family favorite!

  21. I loved this recipe so much, I’ve already baked it again, but adding dark chocolate crumbles on top of the topping. Wondering about trying persimmon pulp with some cranberries in place of blueberries and lemon juice. What do you think?

  22. My recipe didn’t not cut into bars like the picture. It was more of a Blueberry crisp and I have to say it was the best ever! Will be making this again.

  23. Yummy filling and topping. I took this recipe but I halved the topping, and put a shortbread bottom. So good!!!