Cut chicken into 4 pieces. Place each chicken breast between 2 sheets of parchment paper or plastic wrap and pound out to ¼-inch thick. Add chicken to a plate and drizzle 1 tablespoon lemon juice over the chicken breasts. Sprinkle both sides with a little salt, pepper, and garlic powder.
To make bread crumbs: Toast bread and break into pieces. Add to a blender. Grind into crumbs. Place the bread crumbs on a plate. In a shallow bowl, add the egg and beat well. Dip each chicken breast first in the egg, then bread crumbs.
In a large nonstick pan, spray a generous amount of olive oil spray. Add olive oil, to heat. Add the breaded chicken breasts. Cover pan and cook chicken for 3 minutes. Using a spatula, carefully turn over chicken, cover, and cook for about more 2 minutes until chicken is cooked through. Remove from pan and set aside while you make the sauce.
To make the sauce: In a small saucepan, melt butter. Add chicken broth, wine and lemon juice and a little salt, and pepper. Boil over medium-high heat until reduced in half, about 2 minutes. Stir in capers.
To serve: add 1 chicken breast to each plate. Divide sauce and spoon over each chicken breast. Sprinkle a little scallions or chives over each serving, if desired.