Blueberry Crumb Bars
- By Amy Dong
- Updated Jul. 4, 2025
I keep this Blueberry Crumb Bars recipe on standby all summer. The filling is bright and juicy, the crust is buttery and crisp, and the cinnamon crumble gives them that little something extra. Delicious chilled or reheated.
In This Article
This post may contain affiliate links, at no additional cost to you.
Video: Watch Us Make This Recipe
Amy’s Notes
These Blueberry Crumb Bars are one of my all-time favorite blueberry recipes. Here’s why they always stay on my baking list:
- Loaded with Fresh Berries: Each bite is packed with juicy blueberries that burst as they bake. It feels like the best parts of Blueberry Pie and Blueberry Crumble all in one.
- Buttery Crust and Topping: The bottom layer is tender and rich, while the cinnamon crumb on top bakes up perfectly crisp.
- Easy to Make Ahead: I usually bake these bars a day early so they have time to cool and set. They slice cleanly and hold together beautifully, which makes them great for sharing. They remind me of my Baked Blueberry Oatmeal.
- Delicious Warm or Cold: I like mine chilled straight from the fridge, while my husband likes them warmed up with a scoop of ice cream. Either way, they never last long.
Key Recipe Ingredients
- Fresh Blueberries – Plump, juicy blueberries burst with sweet-tart flavor and create a luscious filling that’s the star of these crumb bars.
- All-Purpose Flour – Forms the sturdy base and crumbly topping, giving the bars their signature pie-meets-crumble texture.
- Cold Salted Butter – Cut into the dry ingredients to create a rich, tender crust and a crispy, golden crumb topping.
- Cinnamon – Adds a warm, fragrant note to both the crust and topping, perfectly complementing the sweet blueberries.
- Lemon Juice & Cornstarch – Fresh lemon juice brightens the filling, while cornstarch gently thickens the blueberry juices so the bars set up beautifully.
Substitutions And Variations
Here are some of our favorite substitutions and variations:
- Berry Options: Fresh blueberries are perfect for these bars, but you can also use blackberries, raspberries, or chopped strawberries.
- Add Nuts: Stir toasted chopped walnuts, pecans, or almonds into the topping for extra crunch and flavor. Sprinkle them on top before baking.
- Sugar Choices: Granulated sugar keeps the bars light and classic. For a deeper flavor, try using half brown sugar in the crust and topping.
Step-By-Step Recipe Instructions
- Prepare the crust and topping mixture.
- Stir together blueberry filling ingredients.
- Press half of mixture into a greased pan.
- Layer blueberry filling.
- Top with rest of the crumble mixture.
- Bake for 45-50 minutes and serve.
For full list of ingredients and instructions, see recipe card below.
How To Prep Ahead
Take a look at our best prep-ahead strategies for this recipe:
- Bake Ahead and Chill: These blueberry crumb bars are perfect for making ahead. In fact, they need time to cool completely so they can set properly for clean slices. Bake the bars up to 2 days in advance and let them cool fully at room temperature before covering and refrigerating.
- Freezer-Friendly Option: Fully baked and cooled bars freeze well. Cut them into squares, layer with parchment in an airtight container, and freeze for up to 1 month. Thaw in the fridge overnight or on the counter for a couple of hours before serving.
Did you make this?
Please give us a rating and comment below. We love hearing from you!
Blueberry Crumb Bars
Ingredients
For the Crust & Topping:
- 3 cups all purpose flour
- 1 cup sugar
- 2 teaspoons ground cinnamon
- 1 teaspoon baking powder
- ¼ teaspoon table salt
- 1 cup cold salted butter, sliced into cubes
- 1 large egg
For the Filling:
- 4 cups fresh blueberries
- ½ cup sugar
- 4 teaspoons cornstarch
- 3 tablespoons lemon juice, freshly squeezed from one lemon
Instructions
- Preheat oven 375F with rack on lower middle position. Grease a 9×13 baking pan and set aside.
- In a bowl, hand-whisk the flour, sugar, cinnamon, baking powder, and salt. Use a pastry cutter to cut in the cold butter. Add the egg and continue to cut in with pastry cutter until dough becomes a crumbly consistency. Evenly press half of the dough into greased pan (see video for tips.)
- In a large bowl, hand-whisk together the sugar, cornstarch, and lemon juice. Use a rubber spatula to gently fold in the blueberries to coat. Softly spread blueberries evenly over crust, including excess juice from the bowl. Evenly sprinkle remaining topping dough over the blueberry layer.
- Bake 45-50 min or just until topping is golden brown. Let dessert cool completely at room temp before cutting into squares (may be easier to cut when chilled) Serve bars chilled or re-heated, with ice cream or freshly whipped cream.
Notes
- Use fresh, plump blueberries for the best burst of juicy sweetness. If using frozen, keep them frozen right up until mixing to prevent extra liquid.
- Make sure your butter is very cold before cutting it into the flour mixture. This keeps the crust and crumb topping tender and flaky.
- Use a pastry cutter to work in the butter and egg until the dough is crumbly. This creates the perfect texture for both the base and the topping.
- Press the bottom crust evenly into the pan using the bottom of a measuring cup or glass. This simple trick helps form a sturdy layer that holds the filling without crumbling.
- Let the bars cool completely at room temperature before slicing. This allows the filling to set so you get clean, neat squares.
- This recipe is part of our Dessert Bar Recipes Collection.
- Serve the bars chilled for a firmer texture or warm them slightly for a softer, pie-like treat. Either way, they’re incredible with a scoop of vanilla ice cream.
Nutrition (per serving)
Frequently Asked Questions
Yes, you can use frozen blueberries. Keep them frozen until you’re ready to mix them into the filling to minimize excess liquid. Be aware that the filling may be a bit juicier with frozen berries.
Letting the bars cool completely allows the blueberry filling to set up properly. If you cut into them too soon, the filling may run and the bars won’t hold their shape as neatly.
Press the bottom crust mixture evenly into the prepared pan using the flat bottom of a measuring cup or glass. This helps create a compact layer that bakes up sturdy enough to hold the juicy filling.
They’re delicious either way. Some people love them chilled straight from the fridge, while others prefer them gently reheated in a toaster oven. Both ways are fantastic, especially with a scoop of creamy vanilla bean ice cream or a dollop of stabilized whipped cream.
These bars keep well for up to 3 days covered at room temperature. For longer storage, refrigerate them for up to 5 days. They also freeze well for enjoying later.
More to Bake And Eat
- Lemon Bars with Shortbread Crust – These are by far the best lemon bars we’ve ever tried. They’re handed down by an old friend who was famous for her lemon bars.
- Chewy Apple Oatmeal Bars – These delicious bars are perfect for those who have gluten and dairy sensitivities. But really, they’re for anyone who simply loves apples + oats.
- The Best Apple Pie Bars – Speaking of apples, if you love apple pie, these bars will serve you very (very) well. They’re much easier to make and every bit as delish.
- Chewy Monster Cookie Bars – No, these cookie bars do not contain fruit. Yes, they are genuinely worth every single bite. Take them to your next party or picnic and watch them disappear.