Preheat oven to 275 degrees F. (Yes, this low temperature is correct.) Grease a 9x13-inch baking dish with nonstick spray. Set aside.
Slice each chicken breast in half horizontally; creating two even pieces (cutlets). You will have 4 cutlets total. Pound each cutlet into an even 1/2-inch thickness. Place the milk in a shallow bowl, and the breadcrumbs in separate shallow bowl. Dip each chicken cutlet thoroughly in milk, then coat with breadcrumbs.
In a large skillet, melt butter over medium heat. Place the coated chicken cutlets in the skillet and cook until golden-brown on each side; being careful not to burn.
Place the partially cooked chicken side by side in the prepared baking dish. Bake in the oven to finish cooking while you prepare the basil cream sauce. (The chicken takes about 10 minutes to finish in the oven. The internal temperature of chicken needs to be 165 ℉)