In a heavy bottomed saucepan over medium-high heat, cook the diced apples, butter, brown sugar, lemon juice and 2 Tbsp of granulated sugar. Cook for 5 minutes to allow the apples to release their juice.
Add the flour, cinnamon, nutmeg and salt. Stir until the flour has been absorbed by the juices, then lower the heat and cook for an additional 5-7 minutes until thickened and reduced. Remove from the heat and add vanilla. Cool completely. [I often made this the day before and refrigerate for a timesaver.]
To assemble: Preheat the oven to 400°F. Line a baking sheet with parchment paper.
On a lightly floured counter, roll out the pie crust. Cut into 10 [5"] rounds re-rolling the scrap pieces as needed.
Brush the edge of each round with the beaten egg wash then spoon 2 Tbsp of the filling onto one side of each round.
Gently fold the dough over the filling, and press the edges together using a fork to seal.
Place onto a parchment lined baking sheet. Cut a slit in the top of each hand pie, and brush with beaten egg wash.
Sprinkle with the remaining 1 Tbsp of granulated sugar.
Bake for 20-22 minutes until golden. Some of the filling, may ooze from the pies while baking.