Brush bottom of a 16-by-11-inch rimmed baking sheet with olive oil. Press and stretch dough evenly to cover bottom of sheet. (If dough resists at first, let it rest for a minute and then continue.)
Spread sauce in an even layer over dough, leaving a 1-inch border around all sides.
Bake until underside of dough is golden (lift up pizza with a spatula and take a peek), about 15 minutes. Use a ghost-shaped cookie cutter to cut ghosts from cheese.
Place ghosts on top of hot pizza and bake for 5 minutes.
Place two capers on each piece of cheese for eyes.
Let stand 5 minutes on a wire rack before slicing and serving.
