Preheat oven to 350ºF. Roll out both pie crusts from the first package. With a 2″ round cookie cutter, cut out as many mini dough rounds as you can (roll out leftover pieces of dough and make more rounds until dough is used up). Place them on a lightly greased or foil-lined baking sheet. Brush the tops with a thin coating of beaten egg and sprinkle 2 tbsp of sugar evenly over all of the dough rounds. Bake for about 10 minutes, or until lightly golden-brown. Meanwhile, make filling. Peel, core, and cut apples into very thin slices. Place in bowl and toss gently with one teaspoon of lemon juice. Place slices in a medium pot. Add remainder of lemon juice, sugar, butter, cinnamon, and salt. Over medium high heat, stir very gently and cook just to soften apple slices (about 2-3 minutes – do not let the apple slices get mushy). Add cornstarch and incorporate to thicken mixture. Remove from heat and set aside. Remove mini dough rounds from oven. Place 4-5 apple slices on each cooked round. Roll out both pie crusts from the second package. Cut each crust into thin strips, ¼-½” thick. Make lattice design over the apple slices. Gently pinch around the edges. Brush lattice tops lightly with remainder of beaten egg. Sprinkle with decorative sugar and return to oven. Cook until tops are golden-brown (about 15 minutes).