Preheat oven to 400 degrees
In a large bowl stir sugar, cornstarch, lavender, blueberries and butter together
Lay out one pie crust in pie dish and fill with blueberry mixture
Using the remaining pie dough, roll out a top crust for a lattice crust + crimp the edges
Bake pie for 40 to 45 minutes or until juices bubble up over the crust.
Let pie cool completely at room temperature before serving