Spray the mini skull baking tin with cooking spray.
Dust the counter lightly with flour to prevent the dough from sticking. Roll, pat, or stretch the dough out until it is roughly 1/4" thick. Cut the dough into 6 rectangles. Don’t worry if they aren’t perfectly shaped or exactly equal in size.
Working with one piece of dough at a time, lay each dough piece into the skull cavity and start filling it with sauce, mozzarella, a sprinkle of Parmesan cheese and your desired toppings. After adding the toppings, add a little bit of pizza sauce on top before sealing the dough (no more than a tablespoon).
Fold the dough over the fillings, pinching the dough together to seal them (like a small pizza pocket). Continue until the 6 pieces have been filled and sealed.
Refrigerate the skull pizza tray while you preheat the oven.
Preheat the oven to 400 degrees Fahrenheit.
Remove the tray from the refrigerator and bake for 16 to 20 minutes or until lightly golden brown (some pre-made doughs may need more or less time).
Remove from the oven and allow it to cool for 5 minutes. Unmold and serve with marinara sauce and chopped parsley or basil (optional).