• Preheat oven to 375ºF. and grease an 8-inch baking dish.

Crust

• First, use a pastry cutter (or food processor) to combine the flour, butter, and salt. Cut the ingredients together until the butter is incorporated into the flour.
  1 cup all-purpose flour, 8 tablespoons unsalted butter, ½ teaspoon salt
• Next, slowly add the ice water a teaspoon at a time, while mixing with a spoon, until the flour mixture starts to come together.
  2 tablespoons ice water
• Last, remove the dough from the bowl shape into a ball. Wrap the dough in plastic wrap and place it into the refrigerator for 30 minutes.

Filling

• First, a large bowl toss the berries, sugar, cornstarch, cinnamon, and salt together. Next, continue tossing or stirring the filling until the berries are evenly coated. Transfer the berries to the prepared baking dish.
  6 cups mixed berries, 1 cup granulated sugar, 2 tablespoons cornstarch, 1 teaspoon ground cinnamon, ½ teaspoon salt
• After the dough rests for 30 minutes, remove the dough from the fridge and lightly dust your countertop with flour. Use a rolling pin to roll out the dough. It should be about ½ an inch thick. Carefully lay the dough over the berries. Last, trim the edges so that none is hanging over the edge. and tuck in any excess crust if desired.

Egg Wash and Bake

• Mix the egg and water together to make an egg wash. Brush the egg wash over the dough. Then cut 3 to 4 slits into the center of the dough for venting. Place the cobbler into the oven and bake for 35-45 minutes or until the filling is bubbly and the crust is golden brown.
  1 large egg, 1 tablespoon water
• Allow the cobbler to cool for 15-20 minutes prior to serving. Add whipped cream or ice cream as a topping.