These Blueberry Oatmeal Crumble Bars combine a buttery oat crust with a sweet-tart blueberry filling, topped with a crunchy crumble. They’re perfect for a breakfast treat, snack, or dessert that feels wholesome but indulgent.
Why You’ll Love This Recipe
I love how this recipe balances textures and flavors — the oat crumble is buttery and crisp, while the blueberry filling is juicy and bright with just the right hint of lemon. Plus, it’s super easy to make, using simple pantry staples and fresh or frozen berries. It’s a great way to enjoy berries year-round and makes for a beautiful, shareable dessert or snack.
Ingredients
(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)
Crust & Crumble
1 1/2 cups rolled oats
1 1/4 cups all-purpose flour
1/2 cup brown sugar
1/4 tsp cinnamon
3/4 cup butter, melted
Blueberry Filling
2 cups fresh or frozen blueberries
2 tbsp sugar
1 tbsp lemon juice
2 tsp cornstarch
1 tsp lemon zest (optional)
Directions
Preheat the oven to 350°F (175°C). Line an 8×8 or 9×9 inch baking pan with parchment paper.
In a bowl, combine rolled oats, flour, brown sugar, and cinnamon. Add melted butter and mix until the texture is crumbly.
Press about two-thirds of this oat mixture firmly into the prepared pan to form the crust.
In a separate bowl, mix the blueberries, sugar, cornstarch, lemon juice, and lemon zest until well combined. Spread the blueberry mixture evenly over the crust.
Sprinkle the remaining oat crumble mixture evenly over the blueberry filling.
Bake for 35 to 40 minutes, or until the top is golden brown and the blueberry filling is bubbling.
Allow the bars to cool completely in the pan, then chill in the fridge for at least 1 hour to make slicing easier.
Servings and Timing
This recipe makes about 9 to 12 bars depending on how large I cut them.
Prep time is roughly 15 minutes, and baking takes about 35 to 40 minutes. Including cooling and chilling time, plan for around 2 hours before serving.
Variations
I sometimes drizzle vanilla glaze made from powdered sugar and milk on top for a sweeter finish.
Swapping blueberries for raspberries, blackberries, or a mixed berry blend works beautifully.
Adding chopped pecans or shredded coconut to the crumble adds a nice texture twist and a hint of nuttiness.
For a gluten-free option, I use gluten-free flour and oats.
To boost the flavor, I occasionally stir in a pinch of ground ginger or nutmeg to the crumble mix.
Storage/Reheating
I store these bars covered in the fridge for up to 4 days, and they stay fresh and delicious. If I want to enjoy them warm, I heat a bar in the microwave for about 15-20 seconds. They can also be frozen for up to 2 months — I thaw them overnight in the fridge before serving.
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FAQs
How do I prevent the crumble topping from burning?
I make sure to keep the crumble evenly spread and not too thick. If I notice the top browning too quickly, I tent the pan loosely with foil halfway through baking.
Can I use frozen blueberries without thawing?
Yes, I use frozen blueberries straight from the freezer. Just add a little extra cornstarch if the filling seems too watery.
What type of oats work best for this recipe?
I prefer rolled oats because they provide a nice chewy texture. Quick oats might make the crumble too soft, and steel-cut oats are too coarse.
Can I make this recipe vegan?
Absolutely! I swap the butter for a vegan margarine or coconut oil, and ensure the sugar is vegan-friendly.
How can I make the bars more portable for snacks?
I cut the bars into smaller squares and wrap them individually in parchment paper or place them in a sealed container. They travel well and are great for on-the-go snacks.
Conclusion
Blueberry Oatmeal Crumble Bars are one of my favorite ways to enjoy seasonal berries in a simple, wholesome treat. The combination of buttery oats and vibrant blueberry filling always hits the spot, whether as a breakfast bar or a dessert. Once chilled, they slice neatly and store well, making them perfect for preparing ahead or sharing. I hope this recipe becomes a staple in my kitchen just as it has in mine.
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Blueberry Oatmeal Crumble Bars
- Total Time: 2 hours (including cooling and chilling)
- Yield: 9 to 12 bars
- Diet: Vegetarian
Description
These Blueberry Oatmeal Crumble Bars combine a buttery oat crust with a sweet-tart blueberry filling, topped with a crunchy crumble. Perfect for breakfast, snacks, or dessert, they offer a wholesome yet indulgent treat.
Ingredients
1 1/2 cups rolled oats
1 1/4 cups all-purpose flour
1/2 cup brown sugar
1/4 tsp cinnamon
3/4 cup butter, melted
2 cups fresh or frozen blueberries
2 tbsp sugar
2 tsp cornstarch
1 tbsp lemon juice
1 tsp lemon zest (optional)
Instructions
- Preheat the oven to 350°F (175°C). Line an 8×8 or 9×9 inch baking pan with parchment paper.
- In a bowl, combine rolled oats, flour, brown sugar, and cinnamon. Add melted butter and mix until crumbly.
- Press about two-thirds of the oat mixture firmly into the prepared pan to form the crust.
- In a separate bowl, mix blueberries, sugar, cornstarch, lemon juice, and lemon zest until well combined.
- Spread the blueberry mixture evenly over the crust.
- Sprinkle the remaining oat crumble mixture evenly over the blueberry filling.
- Bake for 35 to 40 minutes, or until the top is golden brown and the blueberry filling is bubbling.
- Allow bars to cool completely in the pan, then chill in the fridge for at least 1 hour before slicing.
Notes
Drizzle vanilla glaze made from powdered sugar and milk for a sweeter finish.
Swap blueberries for raspberries, blackberries, or mixed berries.
Add chopped pecans or shredded coconut to the crumble for texture and nuttiness.
Use gluten-free flour and oats for a gluten-free version.
Add a pinch of ground ginger or nutmeg to the crumble for extra flavor.
Store covered in the fridge for up to 4 days or freeze for up to 2 months.
Reheat bars in the microwave for 15-20 seconds to enjoy warm.
To prevent burning, tent pan with foil halfway if top browns too quickly.
Use rolled oats for best texture; avoid quick or steel-cut oats.
For vegan option, substitute butter with vegan margarine or coconut oil.
Cut into smaller squares and wrap individually for portable snacks.
- Prep Time: 15 minutes
- Cook Time: 35-40 minutes
- Category: Breakfast, Snack, Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 bar (assuming 12 bars)
- Calories: approx. 180-210
- Sugar: 12g
- Sodium: 60mg
- Fat: 9g
- Saturated Fat: 5g
- Unsaturated Fat: 3g
- Trans Fat: 0g
- Carbohydrates: 27g
- Fiber: 3g
- Protein: 3g
- Cholesterol: 25mg
