Butterfly chicken breasts and pound them using a kitchen mallet into 1/4-inch thickness.
Season butterflied and pounded chicken breasts with salt and pepper.
Place 1/4 the butter mixture in the center and fold the chicken over the butter to form a tight pocket and bring the chicken sides together underneath to form a round ball. The top of the chicken will be smooth and the bottom will be gathered.
Tightly wrap each ball in plastic wrap, and chill in the freezer until slightly firm, about 30 minutes.
In a medium shallow bowl whisk flour and 2 teaspoons salt of salt.
Whisk eggs together in another shallow bowl.
Add panko bread crumbs, paprika, garlic powder, and onion powder into another bowl and mix.
Take each cold chicken ball and gently press it into the flour mixture to coat it entirely, shake off any excess flour.
Dip into the beaten eggs, then press into the bread crumbs mixture.
Place breaded chicken balls onto a plate, cover with plastic wrap, and return to the freezer to chill for another 15 minutes.