These blueberry crumble bars are a big hit every time I make them. These just might be my new favorite cookie bar recipe. After all, who can resist juicy blueberries and buttery oat crumbles all in one scrumptious bar?
Surprisingly easy to make, they are utterly delicious. With sweet blueberry filling and wholesome oat crust these bar cookies are mouth-watering good. Easy enough to make on a whim but perfectly lavish for a fancier occasion, this is a recipe you will want to make over and over again.
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I have to confess that I love making bar cookies. They are so simple to make and easy to clean up. Just one cooking pan and none of the scooping and scraping dough. Just throw the whole thing in the oven and you are practically done.
These blueberry crumble bars are no exception. They are simple to make and are a perfect combination of crunchy sweet oatmeal based crust with smooth blueberry filling. Fruit and cookie all in one bite!
I especially like the sweet juicy berries that burst with flavor in your mouth. This is a perfect recipe for spring or summer when blueberries start to ripen. You can also use frozen berries for a great treat any time of the year.
The best part of all is that these little gems only take about 15 minutes to prepare and no mixer is needed. Super easy!
Ingredients
The ingredients you’ll need are simple:
- Blueberries
- Cornstarch
- Lemon Juice
- White Sugar
- Flour
- Oats
- Brown Sugar
- Butter
You’ll also need a few panty staples like baking soda and vanilla.
You can use either fresh blueberries or frozen berries. Fresh berries are superb but the frozen ones are always available, whatever the season. I just happened to use frozen. If using frozen berries it is best to defrost them first.
Just to make a note of it you will begin by making the blueberry filling. This will be separate from the crust ingredients. The white sugar goes in the blueberry filling while the brown sugar goes in the crust mixture.
The oats can be either instant or old-fashioned rolled oats. Both will work just fine in this recipe. I prefer the old-fashioned oats because they have a little bit more texture but you can use what ever you have on hand.
Storing
These bars are best if eaten within two to three days. Let cool completely before covering. Store at room temperature in their baking pan with an air tight lid or covered with a bit plastic wrap to seal out the air.
If they seem to be getting a tad bit soggy you can also trade the plastic cover for a clean dish towel and store open to the air. If they are getting soggier too quickly or need to use them past the two or three days you can re-bake them in the oven at 375° for about fifteen minutes then allow to cool.
I don’t recommend refrigerating or freezing them. This tends to make them over soggy and crumbly.
Directions
To make reheat oven to 375°. Grease a 9 by 13-inch baking dish.
Combine blueberries, cornstarch, lemon juice and white sugar in a sauce pan. Bring to a boil, stirring constantly until mixture is thick. This will take about 2 minutes after the mixture comes to a boil. Set aside and let cool slightly while preparing the crust.
Combine flour, oats, brown sugar, baking soda and vanilla. Cut butter into the oat fixture until it resembles coarse crumbs.
Press about half of the crumb mixture into the greased baking dish. Reserve the remaining crumbs for the top crust.
Spread the blueberry filling evenly over the crust. Sprinkle with the remains oat mixture and press down slightly.
Bake for about 25 minutes or until top is just starting to brown. Cool before cutting and serving.
Note: Make sure to combine the cornstarch into the berries, sugar and lemon juice before you begin to heat it up. If you add cornstarch to an already hot mixture it will clump up and not thicken correctly.
Recipe
Blueberry Crumble Bars
Ingredients
For the filling
- 2 Cups Blueberries
- 2 Tb. Corntarch
- 2 Tb. Lemon Juice
- ½ Cup White Sugar
For the Crust
- 1 ½ Cups Flour
- 1 ½ Cups Oats
- 1 Cup Brown Sugar
- ½ t. Baking Soda
- 1 t. Vanilla
- ¾ Cup Butter
Instructions
- Preheat oven to 375°. Grease a 9 by 13-inch baking dish.
- Combine blueberries, cornstarch, lemon juice and white sugar in a sauce pan. Bring to a boil, stirring constantly until mixture is thick. This will take about 2 minutes after the mixture comes to a boil. Set aside and let cool slightly while preparing the crust.
- Combine flour, oats, brown sugar, baking soda and vanilla. Cut butter into the oat fixture until it resembles coarse crumbs.
- Press about half of the crumb mixture into the greased baking dish. Reserve the remaining crumbs for the top crust.
- Spread the blueberry filling evenly over the crust. Sprinkle with the remains oat mixture and press down slightly.
- Bake for about 25 minutes or until top is just starting to brown. Cool before cutting and serving.
Notes
Yes, you can use either fresh blueberries or frozen berries. Fresh berries are superb but the frozen ones are always available, whatever the season. I just happened to use frozen. If using frozen berries it is best to defrost them first.
Yes, the oats can be either instant or old-fashioned rolled oats. Both will work just fine in this recipe. I prefer the old-fashioned oats because they have a little bit more texture but you can use what ever you have on hand.
I don’t recommend refrigerating or freezing them. This tends to make them over soggy and crumbly. Just store at room temperature.
If they seem to be getting a tad bit soggy you can cover for a clean dish towel instead of plastic and store open to the air. If they are getting soggy too quickly you can re-bake them in the oven at 375° for about fifteen minutes then allow to cool.
Yes, absolutely. Just about any other type of fruit will work. Cut up fruit until it is roughly the size of a blueberry. You should be able to use juicy fruits like strawberries or peaches in the same way. For drier fruits like apples or raisins it may be necessary to add some additional water when you combine the fruit and cornstarch mixture. The amount of water will vary depending on the fruit.
You also might like to try my potato chip cookies or oatmeal muffins!
Make sure to leave your questions, comments, and ratings below.
Larissa
This is so delicious!. My family totally loved it. So good with fresh blueberries from my yard.