Preheat oven to 400°F. Line a baking sheet with parchment paper and set aside.
For the chicken sausage: If raw, cook in a 400°F oven to an internal temperature of 160°F using a thermometer. If already cooked: Place in a 400 degree oven until warmed through or slice and brown in a nonstick pan on medium heat.
In a large bowl, combine the apples, lemon juice, vanilla, sugar, cinnamon, pecans, flour and raisins (if using). Stir to coat evenly.
Place the pastry onto the baking sheet and roll it out slightly, using a rolling pin to thin it out a little bit (this will help cut down on cooking time). Optional: make slices about 1 inch thick on both sides of the puff pastry to make a lattice top.
Spread the apple mixture evenly down the center of the pastry lengthwise.
Fold the sides of the pastry around the apples. Seal the dough together by lightly brushing the dough with egg and pressing it together.Optional: Lightly brush the top of the pastry with the egg wash if desired.
Bake for about 25 minutes, until golden brown.
Sit for 5 minutes before slicing, serve warm with chicken sausage. Dust with powdered sugar if desired.