Step 1

Adjust 2 racks to the top and bottom thirds of the oven and preheat to 425 degrees F. Put a baking sheet or pizza stone on the bottom rack.

Step 2

Combine the sugar with 4 cups of the blueberries in a medium saucepan. Bring to a simmer over medium heat, crushing up the berries with a wooden spoon to release their juices, and cook, stirring occasionally, until thick and reduced by half, 15 to 20 minutes. Remove from the heat and stir in the flour and the remaining 2 cups blueberries. Transfer to a bowl and cool completely, about 45 minutes.

Step 3

Meanwhile, fit one of the pie crusts into a 9-inch pie plate and fold and crimp the edges as desired. Refrigerate while you wait for the filling to cool.

Step 4

Line a baking sheet with parchment. Cut out as many stars as you can from the second pie crust. Arrange on the baking sheet. Bake on the upper rack until golden, about 10 minutes. Set aside to cool.

Step 5

Stir the cooled filling once and pour into the dough-lined pie plate; spread it out into an even layer. Place the pie on the preheated baking sheet, turn the oven down to 375 degrees F and bake until the crust in golden and the edge of the filling is bubbly, 55 to 60 minutes. Remove to a rack to cool. Press the stars into the filling, standing them up slightly. Let cool at least 2 hours before serving.