Place the spinach and water in a large, microwave-safe bowl.
Cover and microwave on high for 3 minutes, or until the spinach is completely wilted. Allow it to cool slightly, then transfer the spinach to a clean kitchen towel or cheesecloth and squeeze out as much liquid as possible. Finely chop the dry spinach.
In a medium bowl, combine the chopped spinach, vegan cream cheese, and minced sun-dried tomatoes.
Season with salt and pepper to your liking and mix until everything is thoroughly combined.
Lay the tortillas on a flat surface.
Divide the spinach mixture evenly among them, spreading it over one half of each tortilla.
Fold the empty half over the filling, pressing down gently to seal.
Heat the olive oil in a large skillet or griddle over medium heat. Carefully place one or two quesadillas in the pan, ensuring not to overcrowd it.
Cook for 4-5 minutes per side, until the tortilla is golden brown, crispy, and the filling is warm and gooey.
Repeat with the remaining quesadillas.
Transfer to a cutting board, slice into wedges, and serve immediately.