Preheat the oven to 400°F (200°C) and arrange a rack in the center.
Place the Doritos in a zip-top bag, seal it, and crush into fine crumbs using a rolling pin (or pulse briefly in a food processor).
In a mixing bowl, combine the mayonnaise, sour cream, minced garlic, ground black pepper, and shredded Parmesan until smooth and evenly mixed.
Pat the chicken breasts dry with paper towels and season both sides with the sea salt.
Set up a dredging station with the mayo mixture in one bowl and the crushed Doritos in another. Dip each chicken breast into the mayo mixture to coat all sides, then press into the Dorito crumbs to fully cover, pressing crumbs so they adhere.
Place the coated chicken breasts in a lightly greased 9x13-inch baking dish, leaving space between pieces.
Bake uncovered for 40 minutes, or until the chicken reaches 165°F (74°C) internally and the coating is golden; remove from oven and let rest a few minutes before serving.
