Preheat the oven to 450°F (232°C). Line a baking sheet with parchment paper or lightly grease it with olive oil.
Place the chicken filets on the prepared baking sheet and season both sides with salt and pepper.
Spoon about 1 heaping tablespoon of sour cream onto each chicken filet and spread it evenly over the top.
In a medium bowl, combine the panko, shredded Parmesan, garlic powder, and a pinch of salt and pepper; toss until evenly mixed.
Divide the panko–Parmesan mixture evenly among the 4 filets, pressing the mixture into the sour cream so it adheres and forms a crust.
Bake the filets in the preheated oven for 12–15 minutes, until the chicken is cooked through (no longer pink inside) and the crust is golden and crispy.
Remove from the oven and serve immediately.