Heat the oven to 350°F and lightly coat a 9x13-inch casserole dish with cooking spray. Set the dish aside so the filling can go straight into a prepared pan once the dough is folded in.

Stir the shredded chicken, cream of chicken soup, french onion dip, and cheddar in a large bowl until the mixture looks evenly creamy. The chicken should be coated throughout with no dry pockets of cheese or soup remaining.

Fold the quartered biscuits gently into the chicken mixture, then spread everything evenly in the prepared dish and scatter the french fried onions across the top. Keep the dough pieces distributed rather than stacked so heat can reach the center of the casserole.

Bake uncovered for 25 to 30 minutes. Look for bubbling sauce around the pan edges, a buttery onion aroma, and biscuit tops that are puffed and golden brown.