01 - Preheat the oven to 375°F. Line a baking sheet with parchment paper.
02 - In a small bowl, combine the finely diced strawberries, granulated sugar, cornstarch, lemon juice, and vanilla extract. Mix thoroughly and set aside for 5 minutes to allow the flavors to meld.
03 - On a lightly floured work surface, unroll the two sheets of thawed pie dough. Using a heart-shaped cookie cutter (approximately 3 to 4 inches wide), cut out a total of 16 heart shapes from the dough.
04 - Carefully arrange 8 of the cut-out heart shapes on the prepared baking sheet. Spoon about 1 tablespoon of the prepared strawberry filling onto the center of each dough heart, leaving a clear border around the edges.
05 - Lightly brush the edges of the filled dough hearts with a small amount of the beaten egg. Place the remaining 8 heart-shaped dough pieces on top, aligning them precisely. Gently press the edges together to seal, then use the tines of a fork to crimp the edges securely.
06 - Create a small slit or poke a hole in the top center of each hand pie; this allows steam to escape during baking. Brush the tops of the pies with additional beaten egg wash and, if desired, sprinkle with coarse sugar for added texture and sparkle.
07 - Bake the hand pies in the preheated oven for 18 to 22 minutes, or until the crust is golden brown and the filling is visibly bubbly. Once baked, transfer the baking sheet to a wire rack and allow the pies to cool for at least 10 minutes before serving.