These Blueberry Oat Bars are the perfect spring treat. They start with a buttery oat base, are layered with a sweet blueberry lemon mixture, then topped with more of that crumbly oat mixture and baked until golden.
They're soft in the center, lightly crisp on top and sturdy enough to slice and pack without falling apart. I used my Salted Caramel Bars with Oatmeal as the base for this one and with a few simple tweaks, it turned into the perfect fruit-filled version for warmer weather.
Make a batch for spring gatherings, keep them on the counter for after school snacking or wrap them up for a post game treat.
If you'd like some more post game snacks and treats, try: Simple Peanut Butter Cookies with Chocolate Chips (No Flour), Cinnamon Sugar Pumpkin Blondies or Maple Walnut Spice Cookies.
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Quick Wins 🙌
- Made in one bowl with simple ingredients you likely have on hand
- Great make-ahead option for busy weeks
- Easy to slice, pack and transport
- Sturdy enough for coolers and lunchboxes
- Freezer-friendly
- Works for holidays or everyday snacking
Game Plan 📋
Here's how these blueberry bars fit into your week.
- If you want to get ahead, bake and freeze the bars. Let them thaw at room temperature or toss one into a lunchbox frozen and it'll be ready by snack time.
- Bake a batch on Sunday and keep them covered on the counter or in the fridge for a few days of easy after-school snacks.
- For game days, slice and wrap individually so they're ready to grab on the way out the door.
Ingredients 🛒
Here are notes about some of the simple, everyday ingredients needed for this easy blueberry oatmeal bars recipe.
- Old-fashioned oats: Use old-fashioned oats for the best chewy texture. Quick oats will work in a pinch but give a softer result.
- Butter: Both salted or unsalted butter work fine here.
- Blueberries: Fresh blueberries are best for this. You could use frozen blueberries if fresh ones are not available. Feel free to experiment with other fresh berries that are in season.
- Lemon: Fresh squeezed lemon juice gives you the best flavor. And for an even stronger lemon flavor, try some lemon zest in the blueberry mixture too!
Scroll to the recipe card below for all ingredient amounts and details.
Recipe Variations
- Raspberry oat bars: Swap the blueberries for raspberries. The bright raspberry flavor pairs really well with the buttery oat layers.
- Strawberry oat bars: Use chopped strawberries in place of the blueberries for sweeter fruit filling that's perfect for spring and summer.
- Mixed berry oat bars: Use a combination of blueberries, raspberries and blackberries for a colorful berry filling.
This quick snack has not been tested with these variations. If you give any of these a try, please let me know how it worked out in the comments below!
Equipment Needed 🥄
- 9-inch square baking pan: A metal or glass pan both work well. Lining it with parchment paper makes it easy to lift the bars out for slicing.
- Parchment paper: Lining your baking pan with parchment paper makes lifting the bars out for slicing super easy!
- Small saucepan: You'll use this to cook the blueberry filling. A small saucepan gives the berries enough room to break down and thicken into a jam-like layer without overcooking.
Step by Step Instructions
STEP 1: CPreheat the oven to 350°F and line a 9-inch square baking pan with parchment paper.
In a small saucepan, combine the blueberries, sugar, cornstarch and lemon juice. Heat over medium-low heat for about 8 minutes or until blueberries are soft and mixture is thickened. Set aside while you prepare the oat mixture.
STEP 2: In a medium bowl, combine the oats, brown sugar, flour, baking soda, and salt. Stir until everything is well combined, then add the melted butter and mix until evenly coated.
STEP 3: Press about half of the oat mixture firmly into the bottom of the prepared pan.
STEP 4: Pour the blueberry mixture over the bottom oat layer and spread in an even layer.
STEP 5: Sprinkle the remaining oat mixture evenly over the top.
Bake in the preheated oven for 30 minutes or until the top oat mixture is just starting to golden brown on top.
STEP 6: Remove from the oven and allow to cool completely, about 1 hour.
Using the parchment paper, pull the bars out of the pan and cut into squares.
Expert Tips
Here are some tips for making this blueberry oat bar recipe.
- Serve with ice cream: For the ultimate dessert, serve these with a scoop of vanilla ice cream!
- Press the base layer firmly: When adding the first layer of oat mixture to the pan, press it down firmly so it holds together once baked.
- Cook the blueberry filling until slightly thickened: The filling should look glossy and lightly thickened before spreading it over the base. This helps prevent the bars from becoming soggy.
- Let the bars cool before slicing: This is the hardest part, but it's important. Cooling allows the bars to fully set so they slice cleanly.
FAQ ❓
Yes. Frozen blueberries work well in this recipe and don't need to be thawed first. Add them straight to the saucepan and cook the filling as directed.
You can. If you want to skip the stovetop step, spread about 1 to 1½ cups of blueberry jam or preserves over the base layer instead of the homemade filling.
This usually happens if the bars are cut while still warm. Let them cool completely in the pan so the oat layers and filling have time to set before slicing.
Old-fashioned oats give these bars the best texture, but quick oats will work if that's what you have. The crumble topping will just be a little softer.
Storage
Short-term (2-3 days): Store this sweet treat in an airtight container at room temperature. They usually keep their best texture this way.
Refrigerator storage: Refrigerate them in an airtight container. Let them sit at room temperature for about 10-15 minutes before eating so the oat layers soften slightly.
Freezer storage: These freeze very well. Slice the bars, wrap individually or layer with parchment, and freeze up to about 3 months.
More Recipes To Try
Looking for other recipes to make? Try these:
If you make these Blueberry Oat Bars, I'd love to hear what you think.
Leave a comment and a star rating below to let me know how they turned out. Your feedback helps other readers and helps me keep creating recipes you'll want to make again and again. ❤️
Recipe
Blueberry Oat Bars
Ingredients
- 2 cups blueberries
- 2 tablespoons sugar
- 1 tablespoon cornstarch
- Juice of 1 lemon
- 1 cup flour
- 1 cup old fashioned oats
- ¾ cup brown sugar
- ½ teaspoon baking soda
- ¼ teaspoon salt
- ¾ cup butter melted
Instructions
- Preheat the oven to 350°F and line a 9-inch square baking dish or cake pan with parchment paper.
- In a small saucepan, combine the blueberries, sugar, cornstarch, and lemon juice. Stir to combine and heat over medium heat for about 6-8 minutes or until the blueberries are soft and the mixture has started to thicken. Remove from the heat and set aside.2 cups blueberries
- In a medium sized bowl, combine the flour, oats, brown sugar, baking soda, and salt. Stir well to combine.1 cup flour1 cup old fashioned oats, ¾ cup brown sugar, 1 cup flour, ½ teaspoon baking soda, ¼ teaspoon salt
- Add the butter to the oats mixture and stir to combine.¾ cup butter¾ cup butter
- Press half of the oats mixture into the bottom of the prepared baking dish.
- Spread the blueberry mixture over the oat mixture in the pan.
- Crumble the remaining oat mixture over the top.
- Bake in the preheated oven for about 30 minutes or until the top is starting to turn golden brown.
- Remove from the oven and allow the bars to cool completely.
- Pull the bars out of the pan using the parchment paper and slice into squares.
Video
Nutrition Information
Please note that these nutrition facts are approximations and may not be entirely precise.
Ashlyn Meredith says
We love to make these during berry season!