These Blueberry Oat Bars are the perfect sweet treat. They are simple and easy to make while also being incredibly delicious. The sugar cookie crust is soft, the blueberry jam sweet and tart while pairing perfectly with the oat crumble topping.

Holding a Blueberry Oat Bar in my hand.

I am OBSESSED with these Blueberry Oat Bars.

If I am ever craving a fruity dessert, these are exactly what I want. They’re delicious, easy to make and the perfect treat in the Spring or Summer months.

You can use any flavor jam that you prefer or what you have on hand!

These Blueberry Crumble Bars are the perfect treat to make for yourself, family or a gathering.

Main Ingredients

Ingredients measured out in bowls to make Blueberry Oat Bars.

Why make THESE Blueberry Crumb Bars?

The short answer — they are DELICIOUS.

But let’s talk about these bars in detail.

It all starts with a soft sugar cookie crust. It’s soft and moist in every bite while also having enough structure for you to hold the bar in your hand.

After the sugar cookie crust, we have the blueberry jam filling. While you can always make this homemade, I used Stonewall Kitchen’s Wild Blueberry Jam because it’s my absolute favorite.

Whole Foods also has a delicious Organic Wild Blueberry Jam that is more affordable.

Last, but certainly not least is the crumble topping.

The crumble topping is made with butter, oats, flour and sugar. So it can really do no wrong! It comes together easily and is the perfect complement to the sugar cookie crust.

Blueberry Oat Bar with Layers Labeled.

Tips and Tricks

  • Jam: You want the jam you use in this recipe to be thick, if it is more liquid it will cause issues when baking.
  • Baking: The only tricky part about this recipe is making sure the sugar cookie crust is fully baked before removing from the oven. Use a toothpick to ensure it is fully baked and no crumbs or batter are on the toothpick when removed from the center.
  • Storing: Store in an airtight container at room temperature for up to 5 days. You can also freeze the bars for 1 month and defrost in the microwave when ready to eat.

How to Make Blueberry Oat Bars

  1. Preheat the oven to 350 degrees F
  2. Line a square 8×8 baking pan with parchment paper
  3. Cream together the butter, sugar, egg and vanilla extract until fluffy
  4. Fold in the flour and baking powder until just combined (The batter should be on the thicker side but spreadable)
  5. Transfer the batter to the 8×8 square baking pan and spread it in an even layer
  6. Bake in the oven for 10 minutes
  7. While the crust bakes, make the Oat Crumble Topping. Start by melting the butter then adding the remaining ingredients (It should be a nice crumble with some chunks)
  8. Remove from the oven and spread the blueberry jam on top of the sugar cookie crust in an even layer
  9. Add the Oat Crumble Topping on top until it covers the blueberry jam
  10. Put back in the oven to bake for 35-40 minutes or until the bars are fully baked through
  11. A toothpick should come out of the center clean and make sure the oat topping isn’t over-baked
  12. Remove from the oven and let cool completely before slicing
  13. Use the parchment paper to remove the bars from the pan
  14. Slice and enjoy!
Wet ingredients in a large mixing bowl
Add the wet ingredients to a mixing bowl
Wet ingredients mixed together in a large mixing bowl
Blend until combined and fluffy
Adding the dry ingredients to the wet in a large mixing bowl.
Fold in the dry ingredients
Sugar cookie crust dough in a bowl
Mix until just combined
Sugar cookie crust dough being added to the baking pan.
Scoop the sugar cookie crust into an 8×8 square pan lined with parchment paper
Sugar cookie crust spread out evenly in the baking pan.
Spread out into an even layer covering the bottom of the pan
Adding the blueberry jam on top of the sugar cookie crust.
Add the blueberry jam on top
The blueberry jam spread on top of the sugar cookie crust.
Spread until covered the cookie dough crust in an even layer
The oat crumble topping on top of the blueberry jam ready to be baked.
Make the oat crumble topping and add on top
Sliced Blueberry Oat Bars
Bake and let cool
Holding a blueberry oat bar in my hand.
Slice and enjoy!

Frequently Asked Questions

Are these Blueberry Oat Bars gluten free friendly?

They can be! You just have to use All Purpose Gluten Free Flour and Gluten Free Rolled Oats. You won’t have to change any other ingredients or instructions.

How do I know the Blueberry Crumb Bars are done baking?

You will know the bars are done baking when a toothpick comes out of the center clean. You won’t want to see any crumbs or batter on the toothpick.

Can I use any jam filling in this recipe?

You can! You just have to make sure it’s a thick jam that won’t seep into the sugar cookie crust.

The crust was still a little raw in the middle after baking, what do I do?

If this happens, it means the bars didn’t bake enough.

However, you can also try the method of putting the sugar cookie crust in the oven for about 10 minutes with pie weights before adding the filling. Then continuing with the recipe as instructed.

Are these bars supposed to be eaten warm or cold?

You can enjoy them either way! I like to enjoy them fresh out of the oven and slightly cooled. However, if you’re storing them in the fridge they are just as delicious cold.

You can also heat them in the microwave for about 20-30 seconds to make warm.

How do I store leftover bars?

Store in an airtight container at room temperature for up to 5 days or in the refrigerator for 7. You can also freeze the bars for up to 1 month.

Blueberry Oat Bar on it's side showing the layers.
Blueberry Oat Bar on it's side showing the layers.
5 stars (1 rating)

Blueberry Oat Bars Recipe

Prep Time: 20 minutes
Cook Time: 50 minutes
Total Time: 1 hour 10 minutes
Yield: 16 servings
These Blueberry Oat Bars are the perfect sweet treat. They are simple and easy to make while also being incredibly delicious.
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Ingredients
 

Sugar Cookie Crust

  • 1/2 cup salted butter, softened
  • 1 cup granulated sugar
  • 1 large egg, room temperature
  • 2 tsp vanilla extract
  • 1 1/4 cup all purpose flour, or gluten free all purpose flour
  • 1 tsp baking powder

Blueberry Jam Filling

  • 1 cup Wild Blueberry Jam

Oat Crumb Topping

  • 3/4 cup all purpose flour
  • 2/3 cup rolled oats
  • 1/3 cup dark brown sugar, packed
  • 1/4 tsp baking powder
  • 6 tbsp salted butter, melted

Instructions
 

  • Preheat the oven to 350 degrees F
  • Line a square 8×8 baking pan with parchment paper
  • Cream together the butter, sugar, egg and vanilla extract until fluffy
  • Fold in the flour and baking powder until just combined (The batter should be on the thicker side but spreadable)
  • Transfer the sugar cookie crust batter to the 8×8 square baking pan and spread it in an even layer
  • Spread the blueberry jam on top of the sugar cookie crust in an even layer
  • Now it's time to make the Oat Crumble Topping
  • Start by melting the butter then adding the remaining ingredients (It should be a nice crumble with some chunks)
  • Add the Oat Crumble Topping on top until it covers the blueberry jam
  • Put in the oven to bake for 48-53 minutes or until the bars are fully baked through
  • A toothpick should come out of the center clean and make sure the oat topping isn't over-baked
  • Remove from the oven and let cool completely before slicing
  • Use the parchment paper to remove the bars from the pan
  • Slice and enjoy!

Nutrition

Calories: 289kcal, Carbohydrates: 46g, Protein: 3g, Fat: 11g, Saturated Fat: 7g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 3g, Trans Fat: 0.4g, Cholesterol: 38mg, Sodium: 126mg, Potassium: 60mg, Fiber: 1g, Sugar: 27g, Vitamin A: 325IU, Vitamin C: 2mg, Calcium: 35mg, Iron: 1mg
Author: Jessica Selensky
Course: Dessert, Snack
Cuisine: American
Keywords: baking, Blueberry Oat Bars, Crumble Bars, Easy Desserts, easy recipes, spring desserts, Summer Dessert

If you try this recipe, please consider leaving a rating and comment at the end of this blog post! It is incredibly helpful to my small business and to your fellow readers.