Chop the ham and green onions. Preheat oven to 425, and spray two rimmed baking sheets with cooking spray.
Place three tortillas on each prepared baking sheet. Add cheddar, ham, green onion, then more cheddar to each.
Top each with a second tortilla, then brush each with olive oil.
Bake at 425 degrees for 10 minutes, or until nicely browned. (Swap pans between oven racks halfway through.)
Press quesadillas down with a large spatula or pancake turner, if the tortillas have bubbled up. Use kitchen shears to easily cut each quesadilla into quarters. Enjoy with guacamole (or avocado slices), sour cream, and/or salsa.
Do quesadillas come out a bit better in a pan on the stove top? Sure, and you can of course switch over to cooking them that way if you prefer (or if you’re doing a smaller batch). Oven baked quesadillas are intended to resolve the pancakes issue, where one person is stuck at the stove cooking while everyone else gets to eat them hot off of the pan: This is an easy batch cooking way of making quesadillas for a whole family at once.
Oven Baked Leftover Ham Quesadillas from Mashup Mom: https://www.mashupmom.com/oven-baked-leftover-ham-quesadillas/