Name: Blueberry Oatmeal Crumble Bars
Prep time: 20 min
Cook time: 40 min
Total time: PT-486510H6M6S
Cuisine: American
Ingredients: Crust & crumble: 1 cup all-purpose flour; ¾ cup old-fashioned rolled oats; ½ cup granulated sugar; ¼ cup dark brown sugar; ½ tsp baking powder; ¼ tsp salt; ½ tsp ground cinnamon (optional); ½ cup unsalted butter, melted; 1 egg yolk; Blueberry filling: 2 cups fresh or frozen blueberries; 2 Tbsp fresh lemon juice; Zest of ½ lemon (optional); ¼ cup granulated sugar; 2 tsp cornstarch; Optional add‑ins: ½ tsp vanilla extract in crumble; Chopped nuts (walnuts/almonds)

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Blueberry Oatmeal Crumble Bars are a deliciously rustic dessert that strikes the perfect balance between sweet and wholesome. With a buttery oat crust, juicy blueberry filling, and a crumbly topping, these bars are comforting, satisfying, and incredibly easy to make. They’re ideal for breakfast, snack time, or dessert — and they store beautifully, making them perfect for meal prep or sharing at gatherings.

These bars feature a simple base of oats and flour, lightly sweetened and bound together with butter to form a golden crust. The filling is a mix of fresh or frozen blueberries with a touch of sweetness and lemon for brightness. The same mixture used for the crust is crumbled over the top, creating that irresistible crumbly finish. These bars are highly versatile and can be made gluten-free or vegan with a few substitutions, and you can easily swap the fruit to suit the season. Whether you’re baking for your family, a picnic, or just craving a fruity treat, these Blueberry Oatmeal Crumble Bars are sure to become a favorite.

Why You’ll Love This Recipe

Bursting with juicy blueberry flavor.
Easy, no-fuss recipe with pantry staples.
Great for breakfast, snack, or dessert.
Freezes well and perfect for make-ahead.
Customizable with other fruits or dietary needs.

Ingredients

All-purpose flour
Old-fashioned rolled oats
Brown sugar
Granulated sugar
Baking powder
Salt
Unsalted butter
Vanilla extract
Fresh or frozen blueberries
Cornstarch
Lemon juice and zest

Variations

Gluten-Free: Use a gluten-free flour blend and certified gluten-free oats.
Vegan: Replace butter with vegan butter or coconut oil.
Fruit Swap: Substitute blueberries with raspberries, blackberries, or a mixed berry blend.
Add nuts: Mix chopped walnuts or almonds into the crumble for added crunch.
Spiced version: Add cinnamon or cardamom to the crumble for a warm, spiced twist.

How to Make the Recipe

Step 1: Preheat and Prep

Preheat your oven to 350°F (175°C). Line an 8×8-inch baking pan with parchment paper for easy removal.

Step 2: Make the Crust and Crumble

In a large bowl, mix flour, oats, brown sugar, granulated sugar, baking powder, and salt. Cut in the butter until the mixture resembles coarse crumbs. Stir in vanilla. Press about two-thirds of this mixture into the bottom of the pan to form the crust.

Step 3: Prepare the Blueberry Filling

In a separate bowl, toss blueberries with cornstarch, lemon juice, and zest. Spread the blueberry mixture evenly over the crust.

Step 4: Add the Crumble

Sprinkle the remaining oat mixture over the blueberry layer, gently pressing it down.

Step 5: Bake

Bake for 35–40 minutes, or until the top is golden and the filling is bubbling. Let cool completely before cutting into bars.

Tips for Making the Recipe

Use cold butter and work it in quickly to keep the crumble light.
Don’t skip the lemon—it enhances the flavor of the blueberries.
Let the bars cool completely before slicing for clean edges.
Use parchment paper for easy lifting and cleanup.
Store bars in the fridge for a firmer texture.

How to Serve

Serve these bars as a breakfast treat with coffee or tea, as a light dessert with a scoop of vanilla ice cream, or as an on-the-go snack. They’re great for potlucks, brunches, or packing in lunchboxes.

Make Ahead and Storage

Storing Leftovers

Store in an airtight container at room temperature for 2 days or in the refrigerator for up to 5 days.

Freezing

Wrap bars tightly and freeze for up to 3 months. Thaw in the fridge or at room temperature before serving.

Reheating

No need to reheat, but if desired, warm individual bars in the microwave for 15–20 seconds.

FAQs

1. Can I use frozen blueberries?

Yes, no need to thaw — just toss with cornstarch and lemon as usual.

2. Can I make this recipe gluten-free?

Absolutely. Use a gluten-free flour blend and certified gluten-free oats.

3. Can I reduce the sugar?

Yes, but reducing it too much may affect texture. Try reducing by 1/4 and adjust to taste.

4. Can I make these bars vegan?

Yes, use vegan butter or solid coconut oil in place of dairy butter.

5. Why are my bars falling apart?

They need to cool completely to firm up. Chilling in the fridge helps set them.

6. Can I use other fruits?

Definitely — raspberries, strawberries, blackberries, or a combo all work well.

7. How do I know they’re done baking?

The top should be golden and the fruit should be bubbling slightly at the edges.

8. What kind of oats should I use?

Old-fashioned rolled oats are best. Avoid quick oats or steel-cut oats.

9. Do I have to use cornstarch?

It helps thicken the filling, but you can substitute with arrowroot powder or tapioca starch.

10. Can I double the recipe?

Yes, use a 9×13-inch pan and adjust the baking time by 5–10 minutes as needed.

Conclusion

Blueberry Oatmeal Crumble Bars are the perfect blend of sweet fruit and buttery crumble — easy to make, adaptable to your tastes, and just the right amount of indulgent. Whether you’re making them for breakfast, a midday snack, or dessert, they’re a crowd-pleaser that’s both homey and delicious. Give them a try and you’ll have a go-to recipe for all seasons — especially blueberry season!