Heat oven to 375°F & spray on the inside of an 8x 11" baking-dish with cooking-spray.
When the breasts are irregular thickness, then pound them (put in a Ziploc-bag and onto a flat-surface) into a even ¾"-1" thickness using a meat pounder.
Sprinkle the breasts with grated Parmesan-cheese & freshly ground black-pepper & set them in the prepared baking-dish.
Whisk together Caesar dressing & sour-cream in a small-bowl. Pour on the Caesar or sour-cream mix over every breasts then sprinkle grated Parmesan-cheese on the top.
Set the prepared chicken in the oven & bake at 375°F for half an hour.
Turn the oven to broil & then broil the breasts an extra 2-4 minutes till the chicken turns golden-brown.
When completed, a meat thermometer should register 165°F when stuck in the thickest aspect of one of their middle-breasts. Remove from the oven, cover loosely with foil & permit chicken to rest for 5-10 minutes before serving.
Serve! You can garnish with chopped-parsley, if desired.