Blueberry Crumble bars are a simple delicious treat… that just happen to also be healthy! This gluten free one bowl recipe is a must try.
Blueberry Crumble Bars Recipe
My 9 ingredient blueberry oat bars are the perfect grab and go breakfast when you’re in a rush! They’re very, very easy to make. These simple healthy blueberry oat crumble bars are topped with the most delicious oat crumble that doubles as the crust meaning less prep for you! Win-win!
They are great for a quick on the go breakfast or snack that are healthy, kid-friendly and super easy to throw together! This recipe is an easy, one bowl, no mixer recipe that takes just minutes to make. There are oats in the crust and crumble mixture. The oats add such great texture.
Making these bars with oat and oat flour means they are gluten free, and healthy! They are a great school safe snack or dessert to bring to a pot luck with dietary restrictions.
Gluten Free Blueberry Crumble Bars Recipe
These bars taste just like blueberry pie thanks to a hint of cinnamon. They are amazing any time of year and one of my favorite treats for spring and summer!
Blueberries have always gone hand in hand with breakfast growing up. I’d have them in my pancakes, added them to my cereal or oatmeal, or I’d enjoy them all gooey in a warm muffin. Blueberries have always been one of my favorite berries so adding them to these delicious bars was a no-brainer for me!
They aren’t too sweet and the blueberry flavor really shines making them perfect for breakfast, brunch, snacks, or a healthy dessert. They’re soft and tender, yet slightly chewy from the oats. I add almond and vanilla extract to the crust and crumble, so you get an amazing hint of nut and just enough sweetness. My mom said they’re one of the best ‘desserts’ I’ve made in a long time.
What is in Blueberry Crumble Bars?
Crumble and Crust Ingredients
- Oat Flour – using oat flour keeps these bars gluten free. You can use store-bought oat flour or make your own by simply adding oats to a blender or food processor and blending until smooth.
- Oats – I love baking with large flake oats rather than instant oats. Instant oats are often processed or more ground down for quicker cooking.
- For gluten free bars ensure your oats state they are gluten free. Oats are naturally gluten free but are often produced and packaged in factories/assembly lines that also process flour so there is potential cross contamination.
- Butter – these healthy bars use as little butter as possible. Butter is needed to keep the crust together and to help the crumble crisp up and stick together while baking.
- Brown Sugar – the rich molasses flavor of brown sugar really elevates the crust and crumble of these bars.
- Baking Soda – just a pinch of baking soda keeps the crust and crumble light and airy.
- Vanilla and Cinnamon – I love the subtle hint of cinnamon in blueberry pie and crumble. Vanilla extract is a more common pantry baking ingredient but I have left a note in the recipe that you can also use a splash of almond extract for an added nutty flavor.
Filling Ingredients
- Blueberries – I love this recipe because you can use fresh or frozen blueberries! Living in Canada we don’t have the pleasure of having garden fresh blueberries all year round so I often use frozen berries for this recipe. Rest assured once summer comes around I’ll be sharing lots of recipes and pictures of our blueberries bushes in our garden!
- Vanilla – the vanilla brings out the natural sweetness of the blueberries and adds a subtle vanilla aroma
- Brown Sugar – I love the flavor of brown sugar, the molasses adds a nice richness to the filling. You can sub for regular white sugar or sweetener of choice.
- Cornstarch – often to make jam or pie fillings a large amount of sugar is needed which act as a sweetener but also thickens the filling. Cornstarch is a healthier alternative than adding more sugar. The cornstarch thickens the filling perfectly… and keeps the bars gluten free too!
How to Make Blueberry Crumble Bars
Full Printable Recipe at Bottom of Page
Prepare the Crust and Crumble
1 Line an 8” x 8” baking dish (or 9” x 9” for thinner bars) with parchment paper. Leave enough parchment paper on both sides to overhang. This overhang will be used as ‘handles’ to pull the bars out of the tray after baking and chilling. Set aside.
2 In a large bowl, mix together all of the crust and crumble ingredients. Use a fork to mash the room temperature butter into the oat flour and oats until the dough starts to come together and forms large crumble pieces. The mixture should be crumbly, not smooth.
3 Place 1 and 3/4 cups of the mixture into the prepared pan and put the remaining mixture in the fridge, this will be used for the crumble topping. Use your hands or the bottom of a cup to evenly press the dough in the bottom of the pan. Ensure the dough is pressed evenly together to form the crust.
4 Place the pan in the fridge to chill the crust while you prepare the filling. This will make it easier to evenly spread the filling over the crust without it crumbling.
Prepare the Blueberry Filling
1 In a medium sized pot on medium heat, add all of the filling ingredients except the cornstarch. Stir continuously until the blueberries start to break down. Use the back of the a spoon or spatula to gently press and breakdown the blueberries. Once the blueberries start to breakdown and release their juices, add in the cornstarch and quickly stir until evenly combined.
2 Bring the blueberry mixture to a boil then the reduce heat to a simmer. Cook for about 5 minutes, or until the mixture is thickened and coats the back of a spoon.
Assemble the Bars
1 Preheat oven to 350°F.
2 Remove the chilled crust from the fridge and pour the blueberry filling mixture on top. Use a spoon or spatula to evenly spread it over the crust.
3 Sprinkle the remaining crumble topping over the blueberry filling.
4 Bake for 25 – 30 minutes or until the filling is bubbling and the crumble topping is golden brown and crisp.
5 Remove from the oven and place the baking dish on a wire rack. Allow the bars to cool at room temperature completely, approximately 1 hour.
5 Use the parchment paper ‘handles’ to remove the baked bars from the baking dish. Slice into 16 bars and serve. The bars are delicious served at room temperature, or chilled fresh out of the fridge.
Tips for the Best Blueberry Crumble Bars
- Room Temperature Butter – when preparing the crust and crumble be sure to use room temperature butter… unless you want a workout! To combine the oat flour and oats with the butter you want the butter to be soft, if not you will be trying to mix the butter into the oats with a lot of elbow grease.
- Chill the Crust – after you have prepared the crust in the baking dish, pop the pan in the fridge while you make the filling. The butter will harden so that when you spread the blueberry filling mixture over the crust it will not crumble your crust.
- Cool the Bars – before slicing the bars be sure to fully cool the bars at room temperature for at least 1 hour, or chill them in the fridge. If you try slicing the bars fresh out of the oven they will crumble and fall apart as the blueberry filling will be too warm. Allow the bars to fully cool and then slice!
Can I Use Instant Oats?
Don’t use quick cook or instant oats because they’re finer than regular oats and cook much quicker with a different texture. Instant oats will make the crust and crumble too dry and crumbly.
Are Blueberries Good for You?
Blueberries are an Antioxidant superfood. They are packed with antioxidants and phytoflavinoids. These berries are also high in potassium and vitamin C, making them the top choice of doctors and nutritionists. Not only can they lower your risk of heart disease and cancer, they are also anti-inflammatory.
Are Blueberry Oat Bars Healthy?
I love the idea of a fruit filled, portable bar, but I’m not a big fan of store processed granola/cereal bars that are often loaded with sugar and preservatives. I find them too sweet and not filling because I’m hungry again in no time. These bars are made with 100% oats that are packed with fiber to keep you full longer!
Make Ahead and Freezing Blueberry Crumble Bars
- Make Ahead – I love making a batch of these healthy bars in advance and having grab and go breakfasts for the week! Simply prepare the recipe as usual and allow the bars to cool. Slice the bars and place in an airtight container in a single layer. Store in the fridge for up to 1 week. You can also individually wrap the bars in parchment paper or plastic wrap for a pre-packaged grab and go breakfast
- Tip – if stacking the sliced bars in an air tight container place a layer of parchment paper or wax paper between the layers to prevent the bars from sticking to each other.
- Freezing – the bars can be frozen in an air tight container in a single layer, or stacked with parchment paper in between the layers. Or my preferred freezing method is to individually wrap the cut bars in plastic wrap. This makes for an easy prepackaged grab and go breakfast, snack or dessert!
Looking for More Simple Breakfast Ideas?
- Banana Bread – one of my families favorite treats! With its super moist texture, rich banana flavor it is a must try. This recipe is so simple and only needs a few pantry staple ingredients.
- Mini Berry Dutch Babies – a cute and easy way to change up your breakfast or brunch. Not only are they easy to make they are incredibly delicious!
- Banana Oat Crumble Muffins – not only a healthier twist on classic banana bread, they are just as delicious. Featuring a sweet and crispy crumble topping these are a must try!
Enjoy!
– Sab
Disclosure: I only recommend products I would use myself and all opinions expressed here are my own. This post may contain affiliate links that at no additional cost to you, may earn me a small commission.
Blueberry Crumble Bars
Equipment
Ingredients
Crust and Crumble
Filling
- 2 1/2 cups blueberries, fresh or frozen
- 2 tbsp brown sugar
- 1 tbsp cornstarch
- 1/2 tsp vanilla extract
Instructions
- Line an 8” x 8” baking dish (or 9” x 9” for thinner bars) with parchment paper. Leave enough parchment paper on both sides to overhang. This overhang will be used as ‘handles’ to pull the bars out of the tray after baking and chilling. Set aside.
Prepare the Crumble and Crust
- In a large bowl, mix together all of the crust and crumble ingredients. Use a fork to mash the room temperature butter into the oat flour and oats until the dough starts to come together and forms large crumble pieces. The mixture should be crumbly, not smooth.
- Place 1 and 3/4 cups of the mixture into the prepared pan and put the remaining mixture in the fridge, this will be used for the crumble topping. Use your hands or the bottom of a cup to evenly press the dough in the bottom of the pan. Ensure the dough is pressed evenly together to form the crust.
- Place the pan in the fridge to chill the crust while you prepare the filling. This will make it easier to evenly spread the filling over the crust without it crumbling.
Prepare the Filling
- In a medium sized pot on medium heat, add all of the filling ingredients except the cornstarch. Stir continuously until the blueberries start to break down. Use the back of the a spoon or spatula to gently press and breakdown the blueberries. Once the blueberries start to breakdown and release their juices, add in the cornstarch and quickly stir until evenly combined.
- Bring the blueberry mixture to a boil then the reduce heat to a simmer. Cook for about 5 minutes, or until the mixture is thickened and coats the back of a spoon.
Assemble and Bake
- Preheat oven to 350°F.
- Remove the chilled crust from the fridge and pour the blueberry filling mixture on top. Use a spoon or spatula to evenly spread it over the crust.
- Sprinkle the remaining crumble topping over the blueberry filling.
- Bake for 25 – 30 minutes or until the filling is bubbling and the crumble topping is golden brown and crisp.
- Remove from the oven and place the baking dish on a wire rack. Allow the bars to cool at room temperature complete, approximately 1 hour.
- Use the parchment paper ‘handles’ to remove the baked bars from the baking dish. Slice into 16 bars and serve. The bars are delicious served at room temperature, or chilled fresh out of the fridge.