Easy Three-Berry Crumble Slab Pie

This informal pie is baked on a sheet pan and serves a crowd! Use frozen berries for a fresh flavor any time of year. You may serve this with whipped cream or ice cream, if desired.

Easy Three-Berry Crumble Slab Pie
Ingredients

Pie:

• 2 tablespoons all-purpose flour  
• 2 eaches 9-inch pie crusts
• 7 cups frozen mixed berries (blackberries, blueberries, and raspberries)
• ¾ cup granulated sugar  
• ⅓ cup arrowroot powder
• ½ teaspoon salt

Crumble Topping:

• 1 cup rolled oats
• 1 cup all-purpose flour  
• ¾ cup packed light brown sugar
• 1 teaspoon apple pie spice
• ½ teaspoon salt
• 7 tablespoons cold unsalted butter  

Instructions
 Step 1
Preheat the oven to 375 degrees F (190 degrees C).

 Step 2
Lightly dust an 11x15-inch half-sheet pan with flour. Carefully place the 2 pie crusts into the bottom of the sheet pan, gently stretching and trimming the crusts to fit the bottom and up the sides of the pan.

 Step 3
Combine berries, sugar, arrowroot powder, and salt in a large bowl; stir well.

 Step 4
Combine oats, flour, brown sugar, apple pie spice, and salt in a medium bowl. Use a pastry knife to cut butter into the oat mixture until butter is evenly distributed throughout and the crumble topping mixture resembles small, uneven pieces.

 Step 5
Pour berry mixture evenly onto the crust and add crumble mixture on top.

 Step 6
Bake in the preheated oven until brown and bubbly, 45 to 55 minutes. Remove and allow to cool for 30 to 45 minutes

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