Place chicken breast and thigh pieces in the bowl of a food processor.
Process until you have a ground chicken meat mixture.
Add 1 teaspoon garlic powder, 1 teaspoon paprika, 1 teaspoon salt, 1 teaspoon black pepper to the ground chicken and mix together.
Wet hands with water and form meat mixture into six patties.
Place patties in the freezer for 45 minutes.
Place 2 cups flour and 1 tablespoon cornstarch in a large bowl.
Coat each patty with the flour/cornstarch mixture, shaking off the excess.
Add 1 teaspoon garlic powder, 1 teaspoon paprika, 1 teaspoon salt, 1 teaspoon black pepper to the flour/cornstarch mixture.
Whisk in club soda until there are no lumps and you have a thin batter.
Heat about an inch of oil in a skillet over medium heat.
Dip each chicken patty in the batter and then fry in the hot oil until cooked through and golden brown on both sides.
Patties should be cooked to a temperature of 165℉.
Use a spatula and transfer patties onto a wire rack to drain while you cook the remaining patties.
Spread mayonnaise on both sides of toasted brioche hamburger bun.
Top with a chicken patty, lettuce and a slice of cheese to serve.