Blueberry Lavender Pie

Bahan-bahan (8 porsi)

• 2 pie crust rounds, chilled
• 6 cups fresh blueberries
• 1/2 cup plus 2 tablespoons granulated sugar
• 3 -4 tablespoons cornstarch
• 2 teaspoons dried lavender
• 1 tablespoon lemon juice
• 2 teaspoons vanilla extract
• 1 tablespoon cold salted butter, cut into small pieces
• 1 egg, beaten