Mixed Berry Slab Pie {Recipe updated 2017}
 
 
Slab pies are similar to regular pies, but made in a big baking sheet. They're easier to slice and great for a crowd. This crust is made with coconut oil and the filling is sweetened naturally with orange juice and honey/maple syrup. It's very delicious! Can be adapted to be vegan friendly.
Author:
Recipe type: Dessert
Serves: 20 servings
Ingredients
Pie Crust: (gluten-free variation below)
Egg Wash: (omit if vegan)
Berry Filling:
  • 8 cups mixed berries, divided (I did 5 cups of blueberries & blackberries and 3 cups mixed raspberries, blackberries, and strawberries)
  • ½ cup maple syrup, honey or a combo of both, or more to taste (can also use cane sugar)
  • ½ cup orange juice
  • 5 tablespoons cornstarch or arrowroot
  • pinch of salt
*Gluten-Free Crust:
  • 4 cups all purpose 1 to 1 gluten-free flour (I used Bobs Red Mill Gluten-Free 1-to-1 Baking Flour)
  • 1 cup tapioca flour (tapioca helps with the elasticity, but can also use additional gf all-purpose flour)
  • 2 teaspoons salt
  • 1⅔ cup palm shortening, grass-fed butter or a combo of both
  • 2 tablespoons coconut sugar, honey or maple syrup
  • 1½ tablespoons distilled white or apple cider vinegar
  • 2 eggs (Helps dough hold together. Can omit, but dough will be more crumbly. Extra water will be needed if omitted.)
  • ⅓ - ⅔ cup water ice cold water, a little more may be needed
Instructions
Regular Pie Crust:
  1. Combine the flour and salt in a large mixing bowl. Add the palm shortening or butter and mix in with a pastry blender until mixture is crumbly and no large clumps of oil are left. Mix in the sweetener and add water slowly, adding just enough to make dough soft and flexible but not wet. If dough is crumbly when you roll it out, it needs more water. Continue to add water until dough is nice and pliable.
  2. Chill for 30 minutes to overnight. Before rolling, remove dough from the fridge and let sit for 10-15 minutes on the counter.
  3. Take ½ of the dough and roll it between two pieces of parchment paper or plastic wrap to keep it from sticking to the pin. Roll it 2–3 inches larger than your pan. Since we're using a 10x15x1-inch baking sheet (could also use a 12x17x1) try to roll it into a 13–18 inch (ish), ⅛ inch thick rectangle. If it's larger that's okay. We'll need to use the leftover scraps for the top.
  4. If you rolled dough on parchment paper, use the paper to invert the dough into the pan and press the dough against the sides and into the corners of the pan. Add scraps of dough to any areas that may be short and press together. Trim the edges and add extra dough to the reserved half. Refrigerate the dough in the pan while preparing the filling.
*Gluten-Free Crust:
  1. Combine the flours and salt in a large mixing bowl. Add shortening or butter and blend into the flour with a pastry blender until mixture is crumbly and no large clumps of fat are left. Mix in the sweetener, vinegar, and the egg. Add water slowly, adding just enough to make dough soft and flexible but not sticky.
  2. Divide dough in half, cover and refrigerate for 10 or 15 minutes. Roll larger half in between two pieces of parchment paper or plastic wrap into a ⅛-inch rectangle 2-3 inches larger than your pan. Since we're using a 10x15x1-inch baking sheet (could also use a 12x17x1) try to roll it into a 13–18 inch (ish), ⅛ inch thick rectangle. If it's larger that's okay. We'll need to use the leftover scraps for the top.
  3. Place the rolled dough into the pan and press the dough against the sides and into the corners of the pan. Add scraps of dough to any areas that may be short and press together. Trim the edges and add extra dough to the reserved half. Refrigerate the dough in the pan while preparing the filling.
Filling:
  1. Place 5 cups of the berries into a large saucepan along with the ½ cup honey/maple syrup. (Since raspberries and strawberries are more delicate, I usually leave those out. But it doesn't really matter either way) Combine orange juice with the cornstarch and a pinch of salt and stir into the berry mixture. Turn the heat up to medium-high, cover with a lid and allow the berries to come to a simmer, stirring occasionally. Continue to cook for a few minutes, until the mixture begins to thicken. Use a wooden spoon to break up some of the berries and release their juices. Remove from the heat and stir in remaining 3 cups of berries (You can also reserve some to put over the top of the filling). Let mixture cool while cutting out the shapes for the top. Add additional sweetener, if necessary, to suit your taste.
Preparing the pie:
  1. Preheat oven to 375F. Roll out the remaining dough about ⅛-inch thin. Use *cutters of your choice to cut out as many shapes as possible (cut close together) and place them on a pan lined with parchment paper.
  2. Gently re-roll the scraps one more time and cut as many shapes out as possible. Keep in mind, the more you work with the dough (with all-purpose flour) it can cause too much gluten to develop creating a tough dough. If you don't want to cut out shapes, you can make a lattice top or roll out another full sheet to cover the entire pie. If you cover the top with a full crust, be sure to cut slits in the dough to release steam.
  3. After you have cut out all of the shapes for the top, it's time to assemble the pie.
  4. Take your pan of crust out of the refrigerator. Pour filling into the crust and place cutouts onto the filling in any manner you choose.
  5. Beat together 1 egg with 1 tablespoon of water. Brush egg wash onto all exposed parts of the pie crust—the cutouts and along the edges. Sprinkle with turbinado sugar. Keep in mind that if you don't top with egg wash, the pie crust won't brown much.
  6. Place pan into the oven on the middle rack and bake for 40-50 minutes. Check the crust after 25-30 minutes and cover any areas that may be getting too brown with aluminum foil. Bake just until until filling is bubbly and crust is golden brown.
  7. Remove and let cool completely before cutting into squares.
***NOTES:
  1. I got the Wilton Star Cutters from Michaels craft store in the cake decorating section.
  2. Gluten-free flour blends vary and so will the results. Keep in mind it's not as elastic as regular all-purpose flour and can break apart easily. I recommend a mix with xanthan gum to help with the elasticity, but it's not required. The egg and butter both help to keep the dough together better. I've tried gluten-free flour with all coconut oil and no egg and the crust is still delicious, just more crumbly.
  3. You can easily half the recipe to make a deep dish pie in a regular pie pan.
  4. I like the mixture of berries, but you can choose to use all blueberries or blackberries instead.
  5. If dough begins to crumble when rolled out, that means it's too dry and more cold water needs to be incorporated into the dough.
  6. You can use different shaped cutters to make the dough for the top, but I don't recommend using tiny cut-outs (1-inch cutters) as they can burn easily. Feel free to also cut long strips for a lattice top or cut out another large rectangle to put a full top crust on the pie. Just remember to cut slits across the top for the steam to escape.
  7. The egg wash gives the dough a glossy golden brown finish. You can also use cream or leave it plain, but crust will stay a light color.
Recipe by Wife Mama Foodie at https://www.wifemamafoodie.com/mixed-berry-slab-pie/