Preheat oven to 400°F. Line a baking sheet with non-stick foil and set aside.
In a shallow dish, combine the crushed French’s fried onions, grated Parmesan, panko bread crumbs, and garlic powder; stir to mix.
In a separate shallow dish, lightly beat the 2 eggs, then whisk in the 2 Tbsp mayonnaise and 2 Tbsp water until blended.
Place the 1/4 cup flour in a third shallow dish.
Working one chicken tender at a time, dredge it in the flour and shake off excess. Dip it into the egg mixture, allowing excess to drip off, then press it into the onion-Parmesan mixture to coat evenly. Transfer the coated tender to the prepared baking sheet. Repeat with remaining tenders.
Lightly spray the coated chicken with cooking spray.
Bake for 20–25 minutes, until the coating is golden and the chicken is cooked through (internal temperature 165°F or juices run clear).
Let the chicken rest 3–5 minutes before serving.