Featuring a juicy blueberry filling and a buttery, crumbly brown sugar streusel, there’s much to love about these blueberry pie bars. The filling and streusel come together quickly, and the crust and crumble topping are made from the same mixture, so there’s no need to dirty an additional bowl. They’re easy to make, transport, serve, and freeze!
If you love blueberry crumble pie, but making pie crust from scratch intimidates you, this blueberry pie bar recipe is the answer. You’ll get the same delicious flavors, but with the welcome ease of making a single “dough” that becomes both crust and topping—no finicky pie crust chilling, shaping, or latticing today!
These Blueberry Pie Bars Are:
Quicker than many fruit fillings—no pitting, peeling, or chopping!
Easier than pie—crust & topping made from the same 1-bowl mixture
Super flavorful, with a jammy blueberry filling between layers of buttery brown sugar oat crust
This is everything you need for juicy blueberry bar perfection:
Crust & Topping Made From Same Mixture
This step really couldn’t be easier. You need 1 bowl and a spatula (no mixer required!), and you’ll use this dough for both the crust and the crumble topping.
All-Purpose Flour: Flour is the base of the crust/crumble.
Oats: Feel free to use either whole rolled oats or quick oats here. Reserve 2 Tablespoons of oats to add to the crumble topping before sprinkling it on top of the blueberry pie filling.
BrownSugar: I love using brown sugar in a dough/crumble like this, because of the moisture and flavor it provides.
Baking Powder: Baking powder keeps the crust/crumble on the lighter side. Without it, the texture would be a little too hard and dense.
Salt, Cinnamon, & Lemon Zest: Small amounts but definitely necessary for flavorful bars. The lemon zest brightens up the blueberry flavor, and a touch of cinnamon adds a warmth that’s reminiscent of homemade pie, like apple pie.
Melted Butter: Using melted butter makes this a stir-by-hand mixture (just like these chewy chocolate chip cookies!). It binds the ingredients together and provides the most delicious buttery flavor. Y-U-M.
Stir everything together until it’s formed large crumbles, with no visibly dry parts. Reserve about 1/3 of this mixture to use as the crumble topping, and press the remaining 2/3 into a 9-inch-square baking pan lined with parchment paper (which makes the bars easy to lift out and slice).
Bake the crust for 10 minutes, to give it a head-start before you top it with the filling. While the crust bakes, make the filling.
Blueberry Pie Bar Filling
Grab these 4 ingredients:
Blueberries: You need about 4 and 1/2 cups of fresh blueberries. If using fresh, give them a rinse. If you want to use frozen, expect a juicier filling. No need to thaw.
Granulated Sugar: Just enough to sweeten the berry filling.
Cornstarch: This is the thickening agent that works to set the filling, and make these blueberry pie bars perfectly sliceable. It’s essential in classic blueberry pie and cobbler, too.
Lemon:Zest it first, and then juice it—you need both zest and juice in the filling. The fresh lemon brightens up the flavor. Without it, the blueberry filling tastes a bit… meh. (And we don’t have time for meh desserts!)
Stir most of the ingredients together on the stove for just a couple minutes, to begin dissolving the sugar and cornstarch. Cook and stir only until the berries are coated and look evenly wet. This doesn’t take long—we’re not going for blueberry sauce here! After you take it off the heat, stir in the lemon zest.
Pour the filling over the pre-baked crust. Stir an additional 2 Tablespoons of oats into the remaining crumble mixture, to give it a little extra volume. Then sprinkle the topping all over the blueberry filling.
Now comes the hardest part of this recipe: the waiting. The bars need to bake for 45-55 minutes, and then cool completely before you can slice them. I know, I’m sorry!
One silver lining: this is a great make-ahead recipe!
How to Cut Neat Squares
Cool baked bars completely, just like you would let a pie cool completely. If you cut the bars into squares while they are still warm, they’ll completely fall apart. If I’m serving these at a party or event, I prepare them the night before just so I know they’ll cool long enough to yield neat squares.
Lift the bars out of the pan using the edges of the parchment paper lining and place the whole thing on a cutting board. Slice squares with a sharp knife and wipe the knife clean between each cut.
Serving Blueberry Pie Bars
I love the handheld nature of dessert bars, but remember, these are blueberry pie bars. They’re gooey, juicy, crumbly, and a bit messy. So I do recommend a fork and plate… or at least a plate and a napkin. Unless you’re willing to risk purple-stained fingers and clothing! *Sally’s Baking Recipes is not liable for blueberry stains.*
These bars are delicious served cold or room temperature, or warm one up and top with vanilla ice cream for an à la mode experience! You can also top them with whipped cream, or a drizzle of lemon glaze from this recipe for lemon strawberry crumb bars.
This is blueberry pie without the hassle of making a homemade pie crust! To prepare these easy blueberry pie bars, layer a buttery brown sugar crust, jammy blueberry filling, and a crumbly oat topping. The crust and crumble topping are made from the same mixture, so there’s no need to dirty an additional bowl. Cool completely before cutting.
Preheat oven to 350°F (177°C). Line a 9-inch square baking pan (I love this one and this one) with parchment paper, leaving an overhang on the sides to easily lift the bars out of the pan. Set aside.
Make the crust: Whisk the flour, 1 cup (85g) oats, brown sugar, baking powder, lemon zest, cinnamon, and salt together in a medium bowl. Add the melted butter and stir until the mixture resembles moist crumbly sand and no dry spots remain. You will have a little more than 3 cups of crust mixture, or about 520g. Press 2/3 of the mixture (about 2 cups/345g—doesn’t have to be exact) into the prepared baking pan. Press it into the pan with your hands, a large spoon or spatula, or the bottom of a measuring cup to form a crust. Bake for 10 minutes, and then remove from the oven to slightly cool.
Make the filling: Place the blueberries, sugar, cornstarch, and lemon juice in a saucepan over medium heat on the stove and stir gently to combine. Cook and stir for 2–3 minutes until the cornstarch and sugar begin to dissolve and the berries look evenly wet. Remove from heat and stir in the lemon zest.
Pour/spread the filling over the warm crust. Stir 2 Tablespoons oats into the remaining crumble mixture, then sprinkle it all over the filling, and lightly press it down with the back of a large spoon or flat spatula.
Bake for about 45-55 minutes, or until the top is lightly browned and the blueberry filling is bubbling around the edges.
Remove from the oven and allow the bars to cool completely in the pan set on a wire rack. Feel free to cover and refrigerate the cooled bars for up to 1 day before cutting into squares.
Lift the cooled bars out of the pan using the overhang on the sides and cut into squares.
Cover and store leftover blueberry pie bars at room temperature for up to 2 days or in the refrigerator for up to 1 week.
Make Ahead & Freezing Instructions: You can refrigerate the cooled bars before cutting into squares, see step 6. Baked and cooled bars freeze well up to 3 months. Thaw overnight in the refrigerator and bring to room temperature, if desired, before serving.
Fresh Blueberries: It’s best to use fresh blueberries in this recipe. If you’d like to use frozen, follow the recipe as written and sub in frozen blueberries (do not thaw). Keep in mind that the filling will be much juicier.
Update in 2023: This recipe used to call for 3 cups (about 525g) of blueberries in the filling, and 1 peeled and sliced apple. To make the blueberry apple version, follow the recipe instructions above through step 3. After spreading blueberry filling onto the warm crust in step 4, top evenly with sliced apple, and then sprinkle remaining crumble mixture on top. Continue with the recipe as written.