Easy Three-Berry Crumble Slab Pie

Ingredients

• 2 tablespoons all-purpose flour
• 2 9-inch pie crusts
• 7 cups frozen mixed berries , blackberries, blueberries, and raspberries
• 0.75 cups granulated sugar
• 0.33 cups arrowroot powder
• 0.5 teaspoons salt

Instructions

1. 1

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

2. 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.

3. 3

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

4. 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.

5. 5

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

6. 6

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