Preheat the oven to 400℉

1. Make the blueberry pie filling. Add the blueberries and lemon juice to a small pot. Whisk the sugar, cornstarch, and cinnamon in a small bowl until there are no more lumps. Stir the sugar mixture into the blueberries and place on the stove over medium-high heat. Stir constantly to prevent burning. The blueberries will release their juice, and the sugar will melt. Continue stirring until it simmers (about 5-8 minutes). Once it begins to simmer, turn the eye down to medium. Continue cooking and stirring until the mixture thickens, about 3 more minutes. Remove from heat and allow to cool to room temperature.
2. Make an egg wash by whisking together 1 egg and 1 tablespoon of water in a small bowl. Set aside.
3. Roll and cut the dough. Lightly dust your work surface with flour. Roll the 2 prepared pie crusts onto your surface. Use a star cookie cutter to cut 24 3.5-inch stars. Each crust will yield about 8 stars from the first rolling. For the remaining stars, gather the dough scraps into a loose ball and use a rolling pin to roll out the dough. You will use 12 stars for the bottom crusts and 12 for the tops. Leave the bottom stars whole. Use a paring knife to cut a tiny slit in each top star. It will vent the pie and allow steam to escape.
4. Fill and assemble the pie pops. Lay the bottom stars onto your work surface and place one lollipop stick in the center. Press it down with gentle pressure to help it stay in place. Add 1 heaping teaspoon of the blueberry pie filling to the center of each star. Place the tops on. Use a fork to crimp and seal the edges. Use your finger to press down where the stick is inserted to create a seal. Lightly brush the tops of each pie with egg wash.
5. Transfer and bake the pies. Use a flat spatula/turner to transfer each pie onto a parchment-lined baking sheet. Bake at 400℉ for about 20 minutes, until golden brown. Remove from the oven and transfer to a cooling rack. 
6. Make the glaze. Add the powdered sugar to a bowl and slowly whisk in the milk and vanilla extract. Whisk until a smooth glaze forms. If it is too thick, add more milk, ½ teaspoon at a time. Keep whisking until you have a thick but pourable glaze. 
7. Decorate the pie pops. Use a spoon to drizzle the vanilla glaze over each individual pie. If you are using sprinkles, add them immediately. They need to go on before the glaze dries. Keep the pies flat while the glaze sets. Let them sit for at least 1 hour. The glaze will be fully set in about 2 hours.