Preheat oven to 400f degrees. Line a baking sheet with nonstick foil or spray with nonstick cooking spray.
Pat the chicken breasts dry with a paper towel (this will help the topping adhere to the chicken breasts.)
Place chicken breasts onto the baking sheet. Spread a tablespoon of mayonnaise on top of each breast. Spread it around evenly to coat (don't forget the sides).
Sprinkle shredded Parmesan cheese onto each piece of chicken.
Bake at 400f degrees for about 40 minutes.
When the chicken has about 10 minutes left in cook time, start working on the sauce. In a medium saucepan, heat up the reserved bacon fat over med-low heat. Once it's warmed, whisk in the heavy cream.
Continue whisking until the mixture starts to bubble a little. Whisk in the sour cream. Finally, add shredded parmesan and garlic powder and whisk some more.
Stir in half the cooked bacon.
To serve, drizzle some of the sauce over each chicken breast and top with rest of the crumbled bacon and a sprinkling of dried parsley (for color.)
Video
Notes
Ground cooked sausage can be used instead of bacon.