Preheat the oven to 375°F (190°C) and spray a 12-cup muffin pan with cooking spray.
Unroll the crescent dough and press seams together to form an 8×18-inch rectangle. Cut into 12 equal squares.
Press each dough square into a muffin cup to form a little cup, using a tart tamper or your fingers to shape.
Place about 1 tablespoon shredded mozzarella into the bottom of each dough-lined cup.
Top the mozzarella with one piece of frozen popcorn chicken (use two smaller pieces if needed to fill the cup).
Spoon about 2 tablespoons spaghetti sauce over each piece of chicken.
Sprinkle roughly 1 tablespoon shredded Parmesan over each cup to cover the sauce and chicken.
Bake for 15 to 18 minutes, or until the crescent cups are golden brown and the chicken is heated through.
Remove from the oven and let cool in the pan a few minutes before transferring to a wire rack or serving plate.