Fried chicken patties: grind your own chicken in a food processor or meat grinder. You can also purchase ground chicken from the store if you can find it. If you've never processed ground chicken before and you own a food processor, chop the meat into small 1/2-inch pieces and add to a food processor, pulse until you have a paste of ground chicken with no large pieces.
Grab a small bowl and pour 1/2 to 1 cup of water into it. You will be using this to dip your hands/fingers in while you're shaping chicken patties and the water helps your hands to not stick to the chicken as much.
In a large bowl add chicken, sugar, salt, garlic powder, and onion powder. Wet your hands and use them to mix up all the chicken and spices. Your hands are the best tool for this, and you will have to use them again in shaping your patties.
Line a sheet pan with parchment and spray with non-stick baking spray if you want. This will help the patties not stick to the surface as much, but it's optional. Take a quarter of a portion of the chicken mixture and spoon it onto the parchment. With wet hands, shape the chicken mixture into a round shape that is like the size of the bun that you have. Do this 3 more times until you run out of the chicken mixture. I found that you'd want your raw chicken patties to be about a quarter to a half-inch thick.
Once your patties are formed, they need to go into the freezer to firm up. You can freeze them for an hour and then if you want, you can remove them from the sheet pan and package them up in freezer-safe bags and store them in the freezer until you plan to use them. I wouldn't store them for more than a few months, but up to a couple of weeks in the freezer should be just fine.
Chicken patty dredging and frying: When you are ready to make your sandwiches, it's time to make the dredging station.
Grab two large dishes. In one dish add your all-purpose flour, salt, ground black pepper, and paprika. Stir it all up. In the second bowl, add your whole egg and buttermilk and whisk to combine.
Remove your frozen chicken patties and one at a time coat them in flour, then dip them in the egg/buttermilk mixture and then back into the flour. You want to make sure they are coated thoroughly after each step. In the end, they should be coated in a thin amount of seasoned flour. Place each flour-coated patty on a plate, cutting board, or cooling rack to wait for frying.
Add at least 2 inches of oil to a large pot and add to medium-high heat on your stove. If you have an instant-read thermometer or frying thermometer, you want to get the oil temperature up to 350 F (176 C).
Fry each patty for 5 to 6 minutes or until they are golden brown. I suggest flipping each patty at about the 3-minute mark and cooking for the rest of the time on the second side.
Rest your fried patties on a cooling rack or a paper towel-lined sheet pan while you cook the rest.
Sandwich assembly: prepare your buns by slicing two buns normally and then cutting the very top and the very bottom off two other buns. You just need the middle parts of these last two buns. The top and bottom can be frozen and used later for breadcrumbs or turned into croutons.
Toast all six bun slices but make sure to put a slice of American cheese on the bottom bun slice before toasting.
To the bottom, toasted slice of the bun, add 2 tablespoons of special sandwich sauce and a small pile of lettuce.
Top the lettuce with one of your fried chicken patties and then top that patty with the middle slice of bun.
On the middle slice of the bun, you will add another 2 tablespoons of special sandwich sauce, more lettuce, and four or five pickle slices.
Top that with a second fried chicken patty and then crown with the top bun.
Serve your Chicken Big Macs and enjoy.