If using fresh berries, rinse and drain well. If using frozen berries, take them directly from the freezer. Place berries in a saucepan. In a small bowl, combine sugar, cornstarch, cinnamon, and salt. Sprinkle sugar mixture over berries. Add lemon juice, stirring to combine. Place saucepan over medium-high heat and cook, stirring, until the liquid in the bottom of the pan comes to a simmer. Reduce heat to medium and cook, stirring frequently, until the mixture starts to thicken, 2–3 minutes. Transfer cooked berries to a bowl and cool to room temperature.

Place a rack on the middle shelf of the oven and preheat the oven to 425°F. Line a baking sheet with parchment paper.

Roll pie dough into a 14-inch square. Cut dough into 16 (3 ½-inch) squares. Place a heaping tablespoon of filling into the center of 8 of the squares. Brush beaten egg along the edges of each filled square. Use a knife to cut a vent into each of the remaining 8 squares. Top each filled square with a vented square and press along the edges with a fork to seal.

Brush the top of each pie with egg and sprinkle with raw sugar. Transfer pies to prepared baking sheet. Bake until pies are golden brown, 18–20 minutes. Remove pies from oven and cool 20 minutes before serving.

Store pies, lightly wrapped, at room temperature for a couple of days; freeze for longer storage.