In a medium bowl, combine the chopped artichoke hearts, softened cream cheese, sour cream, Monterey Jack cheese, cheddar cheese, chopped spinach, garlic powder, salt, and pepper. Mix well until all ingredients are evenly distributed.
Lay out the flour tortillas on a clean surface. Spoon half of the spinach artichoke mixture evenly onto one half of each tortilla.
Fold the other half of each tortilla over the filling to create a semicircle.
Brush the outsides of the folded quesadillas with melted butter.
Heat a large skillet or griddle over medium heat. Cook the quesadillas for 3-5 minutes per side, or until golden brown and the cheese is melted and bubbly.
Remove from skillet, let cool slightly, and cut into wedges. Serve immediately.
Notes
Serve with your favorite salsa, sour cream, or guacamole for dipping.