Preheat the oven to 450°F.
Prepare pie crusts by removing pie crust from the packaging. Unroll one crust on a lightly floured surface. It is important to keep the crusts thick enough to hold the pie filling, so I did not roll the crusts out any thinner than they came in the package.
Use a bowl (6-inch diameter used here), placed upside down, to cut out two circles from the dough. Gently gather together the scraps, roll out just enough to cut two additional circles (you may even need to do one at a time).
Place three crust circles onto a baking sheet sprayed with non-stick cooking spray.
Place a scoop of the blueberry pie filling into the center of the circle.
If desired, place a small piece of butter over the pie filling (this isn’t necessary, it adds a little creaminess to the hand pie).
Use a fork to beat the egg lightly. Then, brush a bit of the egg wash around the edge of the circle to help the sides seal.
Fold the pie crust in half to form a crescent shape. Press down (work from the outer edge in) and then crimp with your fingers or a fork to seal the edges.
Brush the exposed sides of the hand pie with the egg wash. Sprinkle the desired amount of coarse sugar over the egg wash.
Bake for 10 to 12 minutes or until the pies are golden brown and the crust is crispy. (The filling does not need to be cooked so we’re really just cooking the crust here.)