Preheat oven to 350 F.
Place the blueberries in a large mixing bowl, then sprinkle in the sugar, and nutmeg.
Add in the lemon juice, vanilla, then sprinkle in the cornstarch.
Fold the ingredients, then set the bowl to the side.
Take one of the store bought pie crust, and cut it in half.
Now cut the half of crust in small squares.
Toss the small squares/ dumplings into bowl with blueberries.
Fold the ingredients.
Lightly butter or spray a 8x11 bake dish.
Toss in the blueberry mixture, and flatten.
Top the cobbler with the remaining whole crust.
Bake the cobbler for 40 minutes.
Let the cobbler cool.
Serve alone or with ice cream.