Grease the muffin pans or mini individual pie dishes. Lightly dust a surface with flour. Roll the chilled dough in 12" diameter. Use a cookie cutter or the bottom of a 3-inch can and cut the dough into circles (or use the fluted mini pans to cut the dough).
Press the dough into the pie dish or muffin pans. Make sure to press firmly to avoid any air bubbles. Use a fork to prick the bottom of the dish. Place the dish on a baking sheet pan, and refrigerate for 30 minutes.
Meantime, in a bowl, combine, apples, 2 tablespoons butter, cinnamon, brown sugar, flour, and a pinch of salt, stir to combine well.
At this point, preheat your oven to 375ºF. After 30 minutes, remove the prepared pie dough from the fridge. Brush with egg wash, make sure to brush the top edges to get a nice golden-brown crust. Fill them with the apple mixture.
Neatly line the apples into the mini pie dish. Drizzle a teaspoon of the remaining sauce from the apple filling (do not drizzle too much, the melted sugar tends to stick to the muffin pan or pie dish). Top them with the remaining butter before baking.
Bake for 25-30 minutes or until the top bubbles and the crust is golden brown. After baking, while they're still hot, use an off-set spatula and carefully lift them off the pie dish. Be careful not to burn your hands.