Name: Blueberry Slab Pie
Prep time: 30 min
Cook time: 55 min
Total time: 205 min
Ingredients: 2.5 C all-purpose flour; 2 tsp granulated sugar; 1 tsp salt; 1 C unsalted butter (frozen & grated (or cubed) - make sure it is still cold!); 1/2 C ice-cold water; 3 pints fresh blueberries (rinsed thoroughly); zest of 1 orange; 2 tsp fresh squeezed orange juice; 2 tsps Grand Marnier or other orange liqueur; 1 C granulated sugar; 1/4 cup all-purpose flour; 1/2 tsp cinnamon; 1.5 C old fashioned oats*; 1 C brown sugar; 1/2 C all-purpose flour; 1/2 C salted butter (softened)

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The ultimate summer party pie! Blueberry slab pie (also known as blueberry pie bars) is the large-scale version of the best blueberry pie you’ve ever had! A great option for summer potlucks, backyard barbeques, and pool parties.

Close up of a plate with a slice of blueberry slab pie, served with a scoop of vanilla ice cream. The blueberry pie filling and crumble topping are in focus - making this a super enticing photo!

It was difficult to put into words just how good this blueberry slab pie is. This summer pie is just next-level delicious. Blueberries bursting with sweet goodness, flakey and buttery crust, and the perfect crumble topping. Oh, and did I mention there’s a splash of booze in it? Yeah, there’s some hooch in this slab pie recipe, and it’ll leave you wondering why you haven’t liquored-up every pie you’ve ever made before.

Let’s review all the boxes this beauty checks: fabulous blueberry dessert? Check. One of the best desserts for crowds? Check (spoiler alert, this pie is massive). Something your friends have never seen before? Check. One of your new favorite desserts for the summer? Check.

If you’ve been looking for new party desserts to make, give this blueberry slab pie recipe a try for your next gathering!

TELL ME ABOUT THIS BLUEBERRY SLAB PIE RECIPE

Level of difficulty: Moderate to difficult (depending on your pastry experience). This recipe may seem long, but it gives detailed steps for making your own pie crust. However, if you’d prefer to use store-bought pie crust for your dessert recipes, no judgement here! See ‘Helpful Hints’ at the end of this post for a quick note on store-bought crust.

Flavor & Texture: The buttery crust and sweet crumble topping are the perfect companions for the juicy blueberry filling accented by zingy orange.

Time: Including the recommended two hour chill time for your pie crust, you will need around 3 hours and 30 minutes to make this amazing blueberry summer pie.

Photo collage showing the several steps to making these blueberry pie bars. The top left image shows ingredients for this blueberry dessert, the top right image show the pan with crust filled with the blueberry pie filling, the bottom left photo show the uncooked pie now covered with crumble topping, and the bottom right photo shows the baked blueberry slab pie with a slice cut out of it.

4 KEY INGREDIENTS FOR MAKING THIS LARGE BLUEBERRY CRUMBLE PIE

Buttery Pie Crust: A good pie crust creates the perfect base for any pie. This slab pie uses an all butter crust recipe, and is an absolute joy! Light and flaky perfection.

Blueberries: Surprising no one, the star of this blueberry dessert is blueberries. This is the perfect summer pie because blueberries are in peak-season in July and August. I know this because during this time, my husband comes home with at least four pints of blueberries after every grocery store run, even if he just went for milk…fridge space is hard to come by in the summertime! This blueberry pie filling is packed with 3 whole pints of blueberries! YUM.

Orange (juice, zest, liqueur): The fresh orange juice and zest, along with the warmth of the orange liqueur, take this pie from a good summer pie to one that people will rave about. In the dead of winter, when blueberry season is far away, your friends will reminisce about this pie and count down the days until you can make it again.

Old Fashioned Oats: Old fashioned oats add a wonderfully chewy texture to the crumble topping of this pie. I do NOT recommend using quick-cook oats for your topping, they are too delicate and will not create a nice texture.

Top down view of a freshly baked blueberry slab pie. This image is a close up of the bottom left quadrant of the large pan of pie bars.

OVERVIEW: HOW TO MAKE THIS SLAB PIE RECIPE

As previously noted, this recipe is a little longer because making your own pie crust is a bit of a process (but so, so worth it!). Due to length, this section is going to be a bit higher-level than some of my other posts. Make sure to hop down to the recipe card for all the details!

Prepare the crust dough: I recommend prepping your crust in a food processor because it’s fast and easy! You can also use a pastry cutter, fork, or your hands. Once you have prepared your dough, make sure to chill it for at least 2 hours before rolling it out to allow the butter to re-harden. This will give you that flakey crust you are hoping for!
Prepare blueberry filling: While the crust is nearing the end of it’s chill time, place blueberries, orange zest, orange juice, and orange liqueur in a medium sized mixing bowl and toss to coat. Add sugar, flour, and cinnamon to the bowl and toss to coat. Set aside until ready to fill the crust.
Prepare crumble topping: After putting together your blueberry pie filling, add oatmeal, brown sugar, and flour into a medium bowl and mix to combine. Add softened butter and cut in with a fork or pastry cutter until large clumps form. Set aside until you’re ready to assemble your pie.
Roll out pie crust and prepare your pan: When ready to use, place chilled dough onto a floured surface and gently roll out with a floured rolling pin. Start from the center of the dough and work towards the edges. Roll dough onto a rolling pin and transfer to a jelly roll pan. Push into corners. Remove excess dough that folds over the top edge of the pan (you can do this easily by rolling your rolling pin along the edges, this will basically ‘cut’ the dough at the very top edge of your pan).
Assemble your pie: Pour blueberry pie filling into prepared crust and spread into an even layer. Sprinkle crumble topping evenly over the top of your filling. Crimp edges of pie crust with your fingers.
Bake: Preheat the oven to 400°F while preparing your filling and topping. When ready to bake, drop heat to 375°F. Bake for 45-55 minutes until bubbly and crust is lightly browned.
Cool and serve: Cool slightly before serving! Serving with vanilla ice cream is optional, but highly recommended!
Store: Fruit pies can be stored at room temperature for up to 2-days, or in the fridge for up to 4-days. I personally like to store my leftover slab pie in the fridge, and heat up slices when we want to enjoy them.

Close up of a slice of these blueberry pie bars. In the background you can see the pan holding the rest of the bluebery slab pie and another slice of blueberry pie bars on a plate. Each slice of this blueberry slab pie has a scoop of ice cream on top.

time saving option 1: make your pie crust ahead of time

You can pre-make your pie crust dough to save time on the day you’d like to bake your pie!

Your dough needs to chill at least 2 hours before rolling out, but it can chill in your fridge for up to 5 days. You can also freeze pie crust dough for up to 3 months. If you choose to freeze your pie crust dough, place the flattened / wrapped rectangle of dough in Step 5 of the ‘Prepare Your Crust’ section. Thaw overnight in the fridge prior to using for your slab pie.

time saving option 2: use store-bought pie crust

If you don’t want to make your own crust, or want to save time, you can buy pie crust in the frozen section of your local grocery store!

The all butter pie crust recipe used for this slab pie is a ‘double crust’ (aka enough to make 2 pies, or one pie with a top crust). So if you’re going to purchase store-bought pastry, make sure it’s enough for two pies. Then roll out and prepare your crust per the recipe, starting at Step 6 of the ‘Prepare Your Crust’ section.

expert tips

Don’t skip chilling your pie crust dough! Chilling your dough is a very important step in pie making! The chill time allows the butter to harden, and will create the light and flaky crust you are hoping for. If you have warm dough (aka warm butter), your butter will melt before baking, creating a hard, crunchy, and greasy crust. Not what you want.

Do I need to add the crumble right away? Won’t it burn? Nope! Go ahead and add that delicious crumble right away. There will be enough moisture leaving the blueberries to keep the crumble from getting scorched, so just let all those delicious ingredients do their thing!

Should I use fresh or frozen blueberries? This recipe was written with fresh blueberries in mind. However, you can definitely swap out for frozen blueberries (they work great for baking!). Make sure you thaw your blueberries prior to using. You can do this by soaking them in a bowl of warm water for 5-10 minutes. If they’re still frozen, replace the water with fresh warm water. You can also defrost your frozen berries in the microwave on the defrost setting for approximately 30 seconds.

Where I’m from, highbush blueberries (the small, more wild-looking variety) aren’t common to find fresh, but we can get them frozen. Highbush blueberries are very, very good, and would certainly be a welcome addition to any pie!