Preheat oven to 375°. Grease a 11×8-inch or 2-quart baking dish with cooking spray.
In a large bowl, stir together sugars, flour, cinnamon, salt, ginger, and nutmeg. Add apples, rutabaga, vinegar, and vanilla, tossing until well combined. Transfer apple mixture to prepared baking dish.
Let Flaky Pastry Dough sit at room temperature until slightly softened, 10 to 15 minutes. On a lightly floured surface, roll dough to a 14×8-inch rectangle about ⅛ inch thick. Cut into 2-inch squares. Shingle squares on top of apple mixture, leaving open spaces to let steam escape. Brush egg wash onto dough, and sprinkle with sparkling sugar (if using).
Bake for 1 hour to 1 hour and 15 minutes, until golden brown and filling is bubbly. Let cool for 30 minutes before serving. Serve warm with vanilla ice cream, if desired.
Flaky Pastry Dough
In the work bowl of a food processor, add flour, sugar, and salt; pulse 4 times to combine. Add butter; pulse until butter is the size of peas. Add water; pulse until a dough ball forms.
Turn out dough onto a lightly floured surface. Form into a disk and wrap tightly with plastic wrap. Refrigerate for 1 hour.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/apple-rutabaga-cobbler/