Preheat oven 150 degrees F.
Begin by removing the duck breasts with the skins on, and set aside in the refrigerator. Remove the thighs and legs from ducks. Debone the thighs, keeping legs and thighs attached, and lightly pound. With the loose meat, shape the legs into a drumstick.
In a large deep dish, marinate the duck legs in brandy and sugar for 1 1/2 hours. Save the brandy after marinating.
Peel all the apples, and core them, keeping the core and peels. Slice 4 apples thinly, place on a baking sheet, and bake for 2 hours. Once they have baked, remove from oven, and small dice. Reserve remaining apples in acidulated water.
Mix the fois gras with the diced apples, season with salt and pepper, and chill in the refrigerator.
Pull the skin of each duck breast 3/4 of the way down, and season with salt and pepper. Place foie gras and apple mixture on flesh, place skin over to seal, and form with your hands. Using the caul fat, wrap each breast tightly and freeze for 2 hours.
Preheat a deep fryer to 360 degrees F.
Lightly dust the duck legs with flour and dip in beaten eggs. Place legs in corn flakes and deep fry for 2 to 3 minutes, remove, and set aside.
Remove the duck breast from the freezer, sear on high heat for 1 to 2 minutes. Remove from heat and set aside in the refrigerator.
To make the mashed potatoes, simply boil the potatoes until fork tender or about 25 minutes. Add in the butter, sour cream, salt and pepper, and mash until desired consistency.
Preheat oven to 350 degrees F.
Slice 3 cored apples into rings and shape with a cookie cutter. Place a slice in each for 4 to 6 buttered ring molds. Using a piping bag, pipe a thin layer of mashed potatoes on the apple slices. Add a layer of thinly sliced black truffles, repeat until tower is 2 1/2 inches tall, and bake for 15 minutes. Raise the oven temperature to 400 degrees F.
Using the leftover peels and cores, add to the brandy in a saucepot and flambe. Once flame is gone, reduce the brandy to a light syrup and strain. Add this to the duck reduction (you may use store bought reduction if you do not have any), and reheat, but do not bring to a boil.
Julienne the remaining apple and deep fry until crispy. Drain excess oil on a paper towel and set aside.
Slice duck breasts and place it in a 400 degree F oven for 4 minutes. Place fried duck legs in oven and heat up for 4 minutes.
To serve, arrange apple tower on plate. Place duck leg, breast, and sauce on plate. Garnish tower with fried apples.