Blueberry Crumb Bars – the most delicious recipe for blueberry crumb bars that are made with real, simple ingredients! Everyone is going to love this summer dessert that would be perfect for the 4th of July, a potluck, or backyard cookout!

These delicious Blueberry Crumb Bars are going to be the highlight of your summer! Made with real, simple ingredients, these dessert bars have a crumbly, crisp crust with a slightly sweet inside. The perfect fruit bar to make this blueberry season!

The Best Blueberry Crumb Bars

Every summer we love to use all the fresh produce at the farmer’s market to make a strawberry rhubarb pie or blueberry crisp! So we knew we needed to develop a simple recipe to make that blueberry crisp into a bar, which is much easier to share at a potluck, picnic, family gathering, or backyard cookout.

These blueberry bars are simply the best way to enjoy this classic summer fruit as a dessert! The lemon juice and zest keep things light and refreshing with a bit of sugar to counter the tartness of the blueberries. They will quickly become the new family favorite!

What You Will Need

  • brown sugar & cane sugar – a combination for the perfect added sweetness – coconut sugar is an easy substitute here too.
  • all-purpose flour – can easily be substituted for 1-to-1 gluten free flour if you want to make gluten-free bars.
  • rolled oats – these bring some added texture and nutrition. If you are making them gluten-free, make sure these are certified gluten-free on the package.
  • ground flax – great for an added nutritional punch!
  • kosher salt – just a pinch!
  • egg – helps with binding that the crust together.
  • vanilla extract – just a little bit for some added flavor!
  • butter – this is what makes your crust & topping nice and golden brown. Use regular or dairy-free butter if you prefer.
  • cornstarch – added to the blueberries so that the filling doesn’t get too runny.
  • lemon juice & lemon zest – a little bit of acidity to lighten and brighten these crumble bars.
  • fresh blueberries – we love using fresh, especially when they are in-season, but frozen would also work just fine.
  • ground nutmeg – added for some great flavor!

How To Make Blueberry Crumb Bars

To get this blueberry crumble bar recipe started, grab your trusty 9×13 baking pan, place some parchment paper in the bottom, and spray with non-stick cooking spray.

Now combine flour, oats, sugars, flax, and salt in a large bowl. Set to the side.

In a separate bowl, whisk together the egg and vanilla extract. Pour that into the flour mixture and stir to combine.

Next, add the cubed butter (make sure it is soft) and cut it into the flour mixture with a fork.

Then pour half of this crust mixture into the bottom of the prepared baking pan and use your hands to press it down firmly, filling the entire bottom of the pan.

Now that you have the crust ready, you can mix the blueberry filling. In a mixing bowl, mix together the cornstarch and cane sugar. Add in the vanilla extract, lemon juice, and lemon zest. Then the fresh blueberries and mix carefully to fully combine.

Can You Use Frozen Blueberries

We prefer using fresh blueberries and highly recommend doing the same, but you can certainly use frozen blueberries too! Just make sure you thaw the blueberries and drain them before using the the recipe. This will help keep the runniness to a minimum.

Pour the blueberry mixture on top of the crust. Then add about 3 tablespoons of brown sugar to the other half of the crust mixture, mix with a fork, and spread this crumble topping evenly on top of the blueberries. Bake at 375 degrees F for about 36-38 minutes.

Let these easy blueberry crumb bars cool completely (especially if using gluten-free flour), cut into squares, and enjoy!

How To Store Blueberry Crumb Bars

If you have any leftover blueberry crumb bars, you can keep them right in the pan, cover with plastic wrap or aluminum foil and place it in the fridge for up to 5 days. Freezing the cooked bars is also an option. Once the pan has fully cooled, cover tightly, and store in the freezer for up to 2 months. The crust and topping will lose some of its crispness, but they will still taste delicious!

Made this recipe and loved it?! We would love it if you would take a minute and leave a star rating and review – it is also helpful if you made any substitutions or changes to the recipe to share that as well. THANK YOU!


Blueberry Crumb Bars – a delicious blueberry crumb bar recipe that is perfect for cabin weekends and cookouts! Tastes like blueberry crisp!


Crust/Topping Mix:

  • 1/2 cup + 3 tablespoons brown sugar
  • 1/2 cup organic cane sugar (or granulated sugar)
  • 2 3/4 cups all-purpose flour (or 1-to-1 gluten-free flour)
  • 1/4 cup rolled oats
  • 1 tablespoon ground flax
  • pinch of kosher salt
  • 1 egg
  • 1 teaspoon vanilla extract
  • 1 cup salted butter, room temp and cubed


  • 1 tablespoon cornstarch
  • 1/2 cup organic cane sugar
  • 1 teaspoon lemon zest
  • 1 tablespoon lemon juice
  • 1/2 teaspoon vanilla extract
  • 4 cups blueberries
  • 1/8 teaspoon ground nutmeg


  1. Preheat oven to 375 degrees F. Line a 9×13 baking pan with parchment, ensuring their flap folded over the sides for easy removal. Spray bottom of pan with olive oil or your favorite non-stick.
  2. In a large bowl whisk together 1/2 of the cup brown sugar, cane sugar, all purpose flour, rolled oats, ground flax and salt. Set aside.
  3. In a small bowl, whisk together the egg and vanilla extract. Pour into flour mixture and stir to combine.
  4. Add butter to flour mixture and cut into flour with a fork.
  5. Pour half of the flour mixture into the prepared baking pan. Spread out evenly and press down firmly with your hands/fingertips to create the crust. Set aside.
  6. Filling: In a medium bowl combine cornstarch and cane sugar. Add lemon zest, lemon juice and vanilla extract. Stir to combine. Add berries and gently combine. Pour blueberries into the pan and spread out evenly.
  7. Take the remaining half of the flour mixture and add 3 tablespoons brown sugar. Use a fork to combine. Crumble the mixture evenly over the top of the blueberries.
  8. Place in the oven, middle rack, 36-38 minutes or until the top starts to become golden brown.
  9. Remove and let cool completely before cutting into squares.


  • Brown Sugar: you can use coconut sugar in place of brown sugar, if you prefer, it will be a bit less sweet.
  • Gluten-Free: to make this gluten-free use 1-to-1 gluten-free flour and gluten-free rolled oats.
  • Dairy-Free: to make this dairy-free use a plant-based butter.
  • Storage: Store covered in the refrigerator for up to 5 days.