Pulse the flour, butter, sugar and salt together in a food processor until the pieces of butter are the size of small pebbles. If you don’t have a food processor, you can also use a pastry cutter or two knives to work the butter into the dough.
Work in the water, one tablespoon at a time, until there are no dry spots left and the dough sticks together. You may not need all of the water.
Divide the dough into two equal-sized pieces. Pat each one into a 3/4”-thick disk, and wrap in plastic wrap. Chill for at least 20 minutes.
Meanwhile, preheat the oven to 375°F.
Sauté the apples in the brown sugar over medium-low heat. Cook, stirring often, until the apples are tender.
Whisk the granulated sugar and cornstarch together in a small bowl, then stir the sugar and the remaining filling ingredients into the apples. Cook, stirring occasionally, until most of the liquid is evaporated, about 5-6 minutes. Remove from the heat.
Roll one disk of the pie dough to a 1/8” thickness. Cut the dough into the size and shape you would like your hand pies to be. Three-inch pies are typically a good size. Circles or squares work well, or you can use a cookie cutter. When choosing a shape, make sure not to choose anything with sharp corners or small appendages (snowflake cookie cutters, I’m looking at you), as they will be difficult to fill.
Spoon 1 1/2 - 2 teaspoons of filling into the center of a cut pie piece, leaving ¼” border at the edges. The exact amount of filling you need will vary depending on the size and shape of your pies.
Brush the edge of the pie with a little beaten egg, and cover with another piece of crust. Use a fork to seal and crimp the edges closed. Repeat with the remaining dough (keep one of the disks in the refrigerator until you are ready to use it so that the dough doesn’t get too soft) and filling.
Arrange the pies on a greased cookie sheet. Brush the tops with beaten egg and sprinkle with the raw sugar.
Bake at 375°F for 15-20 minutes, or until the pies are golden-brown.
You may have some extra filling left. Use it to make more hand pies within a week, or spoon it over pancakes, waffles, oatmeal or ice cream.