This peach and blackberry slab pie is a rectangular pie with a higher crust to filling ratio that easily serves a crowd.

Peach season is JUST around the corner and though I love my winter citrus, I’m looking forward feasting on all the stone fruit and berries that summer has to offer! Peaches and blackberries are a favorite combination of mine. I already have an older classic double crust peach and blackberry pie here on the blog but honestly, the world can never have enough peach and blackberry pie recipes. I’ve been on a bit of a slab pie kick, making cherry slab pie, strawberry rhubarb slab pie, peach slab pie, apricot cherry slab pie with crumb topping, and apple slab pie. So I figure, why not share a peach and blackberry slab pie? It’s the ideal sort of pie for a big potluck or dinner party, as it’s easy to share with large numbers of folks.
What is a slab pie?
Slab pies are exactly what they sound like, a flat slab-shaped pie that is made in a sheet pan or baking pan. Slab pies have an advantage over traditional round pies because they are easy to slice and serve for large groups. Cutting a square or smaller rectangle is easier than cutting a wedge out of a round pie. Slab pies also tend to be thinner than classic pies, with a higher crust to filling ratio.

How do you make this peach blackberry slab pie?
You start by making this pie like any other pie, by making the crust. Combine the whole wheat and all-purpose flour and salt in a bow, then cube up refrigerate cold butter and drop them it over the dry ingredients. Smash the butter with your fingers until they are flat and broken into small pieces about the size of a pea. Sprinkle water over the ingredients and toss until a dough forms. Divide the dough into two 1-inch thick discs, wrap with plastic wrap and then refrigerate for an hour (or overnight).

Once the dough is chilled, make the filling by combining peeled sliced peaches, blackberries, sugar, brown sugar, tapioca starch (or cornstarch), raspberry vinegar, spices, salt, vanilla and almond extract, and a grated green apple all together in a bowl.

Roll out one disk of dough into a 11 x 15 inch rectangle and fit it into a 9 x 13 inch pan. Pour the filling into the dough, and then roll out the other dough into a similar sized rectangle. Cut into strips, weave on top, brush with an egg wash and bake until golden brown and the filling is bubbling.

How do you peel the peaches?
I have a whole detailed blog post on how to peel peaches, because I love peaches so much! But the short answer is you need to blanch ripe peaches in boiling water then shock it in ice water. First boil a large pot of water. While it’s the water is heating up, cut an “x” onto the bottom of the peach with a sharp knife. Fill a large bowl with ice cubes and water. Once the water is boiling, carefully place the peaches in the boiling water, cooking them for 30 seconds. If your peaches are under ripe, you might need to cook them longer, 1 to 2 minutes.
Then scoop the peaches out of the hot water with a slotted spoon and immediately dunk them into the ice water bath. Let them cool until you can handle them, then using your fingers to peel off the skin. They should come off easily!

You can also use a serrated vegetable peeler (<—affiliate link) if you have one, as they work better for peaches than a plain non-serrated vegetable peeler. And if you don’t feel like going through the trouble of peeling the peaches, feel free to substitute nectarines and leave the skin on. Peaches and nectarines are botanically the same but the non-fuzzy skin of the nectarines are thinner and not quite as tough as peaches.
What special ingredients are in this pie?
- Whole Wheat: I use a mix of whole wheat and regular white flour for the crust because the whole wheat has a nuttiness that works well with the fruit. But you can stick with all-purpose if that’s all you have or don’t like whole wheat.
- Paprika: The mild fruity sweet flavor of paprika gives the pie extra dimension, and boosts the orange color of the peaches. I prefer regular paprika and not smoked paprika for this recipe, though you can use smoked paprika if you happen to like the smoky flavor.
- Black Pepper: I use black pepper along with cinnamon in this recipe. It’s very subtle but it gives a little depth to the filling and keeps things interesting. Feel free to omit it if you think it’s too odd (but I think you’ll like it).
- Almond extract: Did you know almond extract is typically made from the pits of peaches, not almonds? It also happen work really well with peaches and other stonefruit like plums and cherries. I love added a dash to my stone fruit pies.
- Green Apple: This is an unusual addition, but I use it a lot in my fruit pies. Green apples, like Granny Smith, are a natural source of pectin, which is a natural fiber that thickens and gels. It’s the fiber that make jams and marmalade thicken and it’s a way to thicken the filling of a pie without having to add tons of starch. If you omit the apple, increase the tapioca starch to 6 tablespoons.
- Raspberry vinegar: I use raspberry vinegar in this recipe because the raspberry flavor boosts the blackberry flavor of the filling, and the acidity of the vinegar both inhibits the browning oxidation of the peaches as well as balances out the sweetness of the filling. Feel free to substitute apple cider vinegar or lemon juice in its place if you don’t have raspberry vinegar.

Tips and Tricks:
- Cold ingredients for pie crust: My favorite pie crust is flaky and buttery. I always recommend using cold ingredients, specifically cold butter and ice cold water.
- Chill the pie crust: Once the pie crust has been made, chill the crust for at least an hour or overnight. This makes sure the butter has solidified and is cold, leading to a flaky pie crust. Chilling overnight also means the water has time to fully hydrate the flour, and the gluten protein in the flour has relaxed. This leads to an easier pie crust to roll out and manipulate.
- Chill the pie before baking: Again, chilling the pie before baking set the pie crust and relaxes the gluten, preventing shrinking of the crust. Chilling also ensure the flakiest result.
- Use store-bought crust: I get some folks don’t want to make their own pie crust. You can sub out store-bought crust if you want. Make sure your pie crust is totally thawed before using it. You might also want to buy an extra pie crust and piece it together to make the rectangle necessary for this slab pie. Serious Eats (where I’m an ongoing contributor), recommends Trader Joe’s pie crust but since I make my own, I haven’t tried it.
- Use frozen or canned fruit: I usually use fresh fruit but you can use frozen or canned fruit. If you use canned fruit, drain it thoroughly otherwise the filling will be soupy. If you’re using frozen fruit, thaw the peaches overnight or in a microwave until there about 50°F. I typically add an extra tablespoon of tapioca starch as well with frozen fruit but that’s optional
- Use a different starch: I use tapioca starch in a lot of my fillings, as I find it gives the filling a nice shiny look while cornstarch tends to dull the color a bit. But you can use cornstarch instead if that’s what you have. If you make a lot of pies though, it might be worth investing in a bag of tapioca starch (<— affiliate link) though!

Storage
Like all pies, this peach blackberry slab pie is best enjoyed the day that you make it. But you can store leftovers it at room temperature for 2 days or in the fridge for up to 4 days. Rewarm and crisp up the pie crust by sticking it in a toaster oven or in a regular oven at 350°F for 10 minutes or so (longer if you have refrigerated it).
You can also freeze this pie! I like to freeze slices of the pie first on a baking sheet until it’s frozen solid, then stored in a freezer resealable bag, with pieces of parchment paper between each piece. Pies can last up to 3 months in the freezer. Just thaw it overnight in the fridge before serving, or thaw it on the countertop for about an hour or so until it’s at room temperature before eating.

If you like this Peach Blackberry Slab Pie, Check out these out fruit pie recipes:
- Strawberry Rhubarb Pie
- Classic Blueberry Pie
- Blueberry Rhubarb Pie
- Summer Fruit Pie
- Grape and Blueberry Pie
- Rhubarb Berry Slab Pie
- Strawberry Meyer Lemon Cream Pie
And here’s a few galettes and tarts recipes as well!
- Blueberry Galette
- Strawberry Rhubarb Galette
- Plum Galette with Almond Frangipane Filling
- Fig and Blackberry Tart
- Apricot Frangine Tart with Rye Crust
- Tarte Tatin
- Mead Poached Pear Galette
- Berry Tart with Blueberries and Strawberries
Peach Blackberry Slab Pie
Ingredients
Crust
- 2 cups all-purpose flour 280 grams
- 1 1/4 cup whole wheat flour 190 grams (or substitute all-purpose in place)
- 1 teaspoon kosher salt
- 1 1/4 cup unsalted cold butter 2 1/2 sticks or 285 grams
- 3/4 cup to 1 cup ice cold water
Filling
- 6 medium ripe peaches about 2 1/2 pounds
- 8 ounces blackberries about 2 cups
- 1/2 cup white sugar 100 g
- 1/4 cup packed light brown sugar 55 g
- 1/4 cup tapioca starch or cornstarch, 35 g
- 1 tablespoon raspberry vinegar can substitute lemon juice or apple cider vinegar
- 1 teaspoon sweet paprika
- 1/2 teaspoon ground cinnamon
- 1/2 teaspoon ground black pepper
- 1/2 teaspoon kosher salt
- 1 1/2 teaspoon vanilla extract
- 1/2 teaspoon almond extract
- 1 Granny Smith apple peeled, cored and quartered
To Finish
- 1 large egg yolk
- 1 tablespoon cold water
- 2 tablespoon turbinado sugar can substitute sparkling sugar or white granulated sugar
Instructions
- Make the pie crust dough by placing the flour and salt in a large bowl. Cut the cold butter into 1/2-inch cubes and sprinkle them over the dry ingredients. Using your fingers, toss the cubes in the flour then smash them into flat pieces, roughly the size of a pea.
- Once all the butter is flattened and broken up, drizzle 2/3 cup of the ice water over the dough and toss with a fork until a dough starts to form. Using your hands massage the dry ingredients gently into the wet parts. If the dough looks too dry, add more water, a tablespoon at a time, until a solid dough forms.Divide the dough into two parts and then flatten each part into a disk about 5-inches wide and 1-inch thick. Wrap each dough with plastic wrap and then refrigerate for a minimum of an hour or overnight (or up to 2 days in the fridge).
- Once the dough has chilled, start prepping the filling. First peel the peaches (see my section above for details on the best way to do that), then slice them to be 1/2 inch thick. Usually this is about 12 to 16 slices per average peach, a little thinner than a typical peach slice. Place them in a large glass, ceramic or plastic bowl. Add the blackberries, white sugar, brown sugar, tapioca starch (or cornstarch), raspberry vinegar, paprika, cinnamon, black pepper, salt, vanilla extract, and almond extract into the bowl. Take the apple and grate it over the filling. Then toss to coat and mix.
- Start assembling the pie. If you’re using a 9 x 13-inch baking pan (the kind that you make brownies in), lightly spray it with cooking oil, then line it with parchment paper. If you are using a 9 x 13-inch rimmed baking sheet (known as a quarter sheet pan), skip this step. Flour a clean surface and then roll out a disk of dough into an 11 x 15-inch rectangle.
- Fold the dough into quarters. Move the dough carefully to the pan. Unfold and fit the dough into the baking sheet or pan, trying to NOT stretch the dough as much as possible. This will help prevent shrinkage.
- Pour the peach and blackberry filling into the pastry dough and then distribute the filling evenly throughout the pan, paying extra attention to make sure the blackberries are evenly distributed all over.Repeat the rolling out of the dough with the remaining disk, making sure it 11 x 15 as well. “Weave” a crust on top, first putting strips of dough in one direction, then alternating and lifting up the dough to weave it into a top crust. You can also just place this dough directly over the pie (to make a double crusted pie) and then cut steam vents into the top with a sharp knife.
- Seal the dough around the edges with your fingers, creating a scalloped edge. Then place it back in the fridge to chill for 20 to 30 minutes. While the pie is chilling, pre-heat the oven to 425°F.Once the pie has chilled and the oven has reached temperature, place the cold pie on a rimmed baking sheet (to catch any overflow spillage). Beat the egg yolk with water, and brush it over the top of the pie. Sprinkle with the turbinado (or white) sugar.
- Bake in the oven for 25 minutes. Then reduce the temperature of the oven to 375°F and continue baking for 25 to 30 minutes, or until the center of the pie is bubbling up through the top crust vents or holes near the center. If the top of the pie crust is starting to brown too quickly, cover with aluminum foil.Let the pie cool for 1 hour on a wire rack for the filling to thicken before serving.
Nutrition
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