01 - Preheat oven to 375°F or heat a large nonstick skillet over medium heat.
02 - Using a ghost-shaped cookie cutter or sharp knife, cut ghost shapes from each tortilla, yielding 2 shapes per tortilla for a total of 8.
03 - Place half of the tortilla ghosts on a parchment-lined baking sheet or plate.
04 - Distribute shredded mozzarella and cheddar cheese evenly over each tortilla base. Add optional diced bell peppers or sliced green onions as desired.
05 - Top each filled base with a second tortilla ghost, pressing gently to seal the edges.
06 - Press 2 black olive slices into the top of each quesadilla for eyes, and add 1 slice or several small pieces for the mouth.
07 - Lightly brush the tops with melted butter or olive oil to promote crispiness.
08 - Bake in oven for 8–10 minutes until tortillas are golden and cheese is fully melted. Alternatively, cook in the skillet for 2–3 minutes per side, flipping carefully until golden and crisp.
09 - Allow quesadillas to cool slightly before serving warm.