Blackberry Slab Pie Bars

blackberry slab pie bars, stacked

Blackberry Slab Pie Bars are a little slice of heaven ~ the flakey pastry, the jewel toned filling, and the sweet glaze all work together in this super user friendly dessert. Use frozen fruit or preserves when fresh berries aren’t available.

blackberry slab pie bars

Give me a blackberry slab pie bar over over a slice of pie any day

They’re just so much more user friendly. You can pick these bars up with your hands, tote them around with you, bring ’em on a driving trip, to work, on a plane…what pie can do all that? And these bars are just as flaky, just as fruity and juicy as any pie. Plus they’ve got that sweet glaze layered over top ~ heavenly!

a stack of blackberry slab pie bars on parchment paper

This is the perfect recipe for a pie-crust-a-phobe (like me!)

I used one of my favorite pastry doughs for these blackberry bars. It’s the dough I used in my Apricot Pie Recipe, and it’s easy to work with, super flaky, with a really lovely softness to it. It’s made with mostly butter and a little shortening which I think makes the difference. It bakes up firm enough so that you can eat these bars by hand, but still quite tender when you bit into it.

glazing and cutting blackberry slab pie bars

The dough is easy to roll and very forgiving

Just push it back together if it cracks, and dust with flour if it sticks. I like to roll it right on the parchment paper it will bake on, so there’s no tricky transfer to deal with, just slide the dough and paper right onto a baking sheet.

This kind of freeform slab pie doesn’t look like much in its whole form, it’s a little ragged, I admit. But just trim the ends a bit before slicing and no one will be the wiser.

making blackberry slab pie bars

how to make a quick blackberry filling for pie bars

These blackberry pie bars would be nothing without the fresh blackberry filling. I made a quick jammy filling by cooking down the berries on the stove with some sugar, lemon juice and thickener. Note: you can use a good blackberry jam or frozen berries to make your filling off season.

  1. Put rinsed berries in a saucepan, along with sugar, thickener, and lemon juice. Stir to combine.
  2. Cook over medium heat, stirring often to dissolve the sugar and allow the berries to release their juices.
  3. Mash the berries with a potato masher or fork and continue to cook for about 8 minutes, or until the consistency of a thin jam.
  4. Chill. It will thicken as it cools.
blackberries with sugar

my favorite thickener for fruit fillings

For the thickener I’ve recently discovered Instant Clearjel, which is a supercharged thickener for pies and fruit fillings. It works like cornstarch, but so much better, and it gives you an added insurance that your fillings won’t be too thin or runny. In this case you definitely want to avoid a dribbly filling!

cooking blackberries

blackberries are healthy, delicious, and stunning!

Blackberries go through a beautiful color transformation when they’re cooked with lemon juice and sugar, the deep blueish purple becomes a brilliant magenta. It’s absolutely gorgeous oozing out of the layers of pastry dough. Like black raspberries, these berries are unsung superfoods, bursting with vitamins and cancer fighting antioxidants.

blackberry filling for blackberry slab pie bars

Please do try these blackberry slab pie bars, you won’t be disappointed

The flakey pastry, the brilliant filling, and the glaze all make this one of my new favorite desserts on the blog. I’ll be reinventing it many times going forward, and I’m definitely doing an apple version for you later this year, so keep an eye out for that.

a blackberry slab pie bar on a napkin with forks

freeze summer berries so you can make this later in the year ~

  • Wash and dry your berries and lay them out in a single layer on a parchment lined baking sheet.
  • Put the whole pan in the freezer until the berries are frozen solid, about an hour.
  • Transfer the berries to a heavy duty zip lock freezer bag and put them back in the freezer. They’ll keep up to a year.
  • Use straight from frozen in pies, jams, sauces, etc.
Frozen blackberries for a frozen blackberry moscato slushie

blackberry recipes to check out before you go!

blackberry slab pie bars, stacked
4.12 from 207 votes

Blackberry Slab Pie Bars

Blackberry Slab Pie Bars are a little slice of heaven ~ the flakey pastry, the jewel toned filling, and the sweet glaze all work together in this super user friendly dessert. Use frozen fruit or preserves when fresh berries aren't available.
Course Dessert
Cuisine American
Prep Time 2 hours 15 minutes
Cook Time 40 minutes
Total Time 2 hours 55 minutes
Yield 16 servings
Calories 242kcal
Author Sue Moran


pie crust

  • 2 1/2 cups all purpose flour, plus more for rolling
  • 1 tsp salt
  • 3/4 cup unsalted butter, cold and cut in pieces
  • 1/4 cup shortening (I used butter flavor Crisco)
  • 1/4 cup ice water

egg wash

  • 1 egg yolk mixed with 2 teaspoons water


  • 12 ounces fresh blackberries
  • 1/2 cup sugar
  • 2 tsp Instant Clearjel thickener (substitute 1 Tbsp cornstarch)
  • juice of 1/2 lemon


  • 1 cup confectioner's sugar, sifted
  • water for thinning


  • Start by making the crust. Pulse the flour and salt a few times in a food processor to combine. Add the cold chunks of butter and shortening to the bowl and pulse about 20 times until the mixture is grainy.
  • Add the ice water, a little at a time, while continuing to pulse, until the dough just comes together when you pinch it between your fingers. Stop the machine to check it. NOTE: you may not need all of the water, but I always do.
  • Turn the dough out onto a floured surface and bring it together into a ball. If there is still any remaining dry flour make sure to knead that into the dough to get it all incorporated. If your dough is too sticky, add a touch more flour.
  • Cut the ball of dough in half, form two flat rectangles, and wrap each one in plastic. Refrigerate the dough for 2 hours (or overnight) before rolling it out.
  • While the dough is chilling make the filling. This step can also be made the day before if you like. Put the berries into a saucepan. Mix the sugar and Clearjel thickener together and add to pan along with the lemon juice. Starting on low and then increasing the heat to medium high, cook the berries until they start to soften and the sugar has dissolved. Mash the berries with a fork as they soften. Stir almost constantly.
  • Cook for about 8 minutes, or until it’s the consistency of a runny jam. I like to mash most of the berries. Chill the filling until ready to use.
  • Preheat the oven to 350F
  • Lay out a sheet of parchment large enough for a baking sheet and lightly flour it. Roll out one of the pieces of dough to (roughly) a 9×13 rectangle. Don’t stress, if it’s close, that’s fine. It helps to let the dough rest for a few minutes to warm up slightly before trying to roll it out.
  • Spoon the jam over the top, leaving about an inch all around free.
  • Roll out the top crust, and carefully place over the jam filling, pressing down all around the edges to seal. if you’ve got excess dough you can roll it up a bit.
  • Brush with the egg wash and bake for about 40 minutes until golden. Let cool before glazing.
  • To make the glaze whisk or stir the sugar together with the water, a tablespoon at a time, until you get a glaze consistency. Brush it liberally over the top of the cooled pie. Let dry before slicing.


Calories: 242kcal | Carbohydrates: 31g | Protein: 3g | Fat: 12g | Saturated Fat: 6g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 4g | Trans Fat: 1g | Cholesterol: 35mg | Sodium: 223mg | Potassium: 59mg | Fiber: 2g | Sugar: 15g | Vitamin A: 328IU | Vitamin C: 4mg | Calcium: 13mg | Iron: 1mg
The nutritional information for recipes on this site is provided as a courtesy and although tries to provide accurate nutritional information, these figures are only estimates.
blackberry slab pie bars pin

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    Leave a Reply

    Please rate this recipe!

  • Reply
    August 6, 2022 at 9:38 am

    How much jam should this make?

  • Reply
    June 20, 2022 at 1:03 pm

    2 stars
    Dough was nice, rolled out well. Filling too tart, needed more sugar. Doubt I’ll make again, too fragile. Will try the dough in a pie pan in the future because I liked the flavor.

  • Reply
    June 18, 2022 at 11:25 am

    These bars look so yummy, am going to be making them this weekend. Love your recipes and the layout of each

  • Reply
    June 18, 2022 at 8:21 am

    These bars look absolutely delectable Sue! Your photos are stunning. I plan to pick up the berries when I go shopping in a few hours as they’re on sale ($2/6oz) – our fresh fruit prices are prohibitive. $5/# for peaches, $6-7/# for cherries. Even apples are $2/#!
    For some reason, I always test the “Cook Mode” button when reading through a recipe – & I couldn’t get yours to work. To be on the safe side – to ensure it wasn’t my device I tested one on another site ? & it worked just fine. So…
    Thanks so much, from Alberta, Canada ??

    • Reply
      June 18, 2022 at 8:27 am

      The? & ?? marks were for a hands-to-cheeks blushing emoji, & the Canadian flag.
      I DID go to another site, no questions asked & I really DO live in Canada! Lol
      Some days….(weeks/months)!

    • Reply
      Sue Moran
      June 18, 2022 at 10:02 am

      Hi Terry, I’ll check on the cook mode issue, thanks!!

  • Reply
    May 29, 2022 at 9:29 pm

    5 stars
    I made these and the recipe was easy to follow. My family LOVED them and are already asking me to bake more! Thank you for posting this recipe!

  • Reply
    July 26, 2021 at 9:36 pm

    5 stars
    This was a great hit at work!

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