Heat a large non-stick skillet over medium-high heat. Place 1 tortilla onto the skillet. Sprinkle about half the Cheddar cheese evenly over the tortilla. Top with spinach, green onions, garlic powder, and chili powder. Cover with the remaining Cheddar cheese. Place the second tortilla on top.

Cook until the bottom tortilla starts to develop a bit of color and starts to crisp, about 3 minutes. To flip and cook the other side, slide the quesadilla off the skillet onto a dinner plate, cover with another plate and flip. The crispy tortilla side should now be on top. Slide the quesadilla back onto the skillet and cook until the bottom tortilla starts turning crisp, about 3 minutes more.