Preheat the oven to 350 degrees F.
To make the filling, first toss the diced apples with the lemon juice to prevent them from turning brown. Then, combine both of the sugars, cornstarch, spices, and water in a medium sauce pan. Stir to combine and bring to a boil over medium-high heat. Whisk this mixture constantly while boiling for abotu 2 minutes or until it is thickened.
Once thickened, stir in the diced apples, and reduce the heat to low. Cover the pot and allow the apple mixture to cook for about 8 to 10 minutes. The apples should be cooked but not mushy. Once cooked, remove the pan from the heat, and set aside to cool.
While the apples are cooling, unroll the pie crust on a lightly floured surface, so that the crust does not stick. The dough needs to be an 1/8 -inch thick. When the apples have cooled, remove the apple from the sauce, and spread them onto the crust. Lay the second crust on top of the apples.
Using a 2 to 3-inch cookie cutter, cut out the cookies. Cut slits in the top of the pie cookies, so the steam can escape as they bake. Then transfer the pie cookies to a parchment lined baking sheet. Brush the pie cookies with the egg wash, and sprinkle with fluer de sel.
Bake the pie cookies in the preheated oven for 20 to 30 minutes or until golden brown. Allow to cool on a rack and serve!