Spinach and Feta Quesadillas

Ingredients

• 4 large flour tortillas
• 2 cups fresh spinach leaves, washed and chopped
• 1 cup crumbled feta cheese
• 1/2 cup shredded mozzarella cheese
• 1/4 cup grated Parmesan cheese
• 1 small onion, finely chopped
• 1 tablespoon olive oil
• 1 teaspoon garlic powder
• 1 teaspoon ground cumin
• 1/2 teaspoon chili powder (optional for a bit of spice)
• Salt
• pepper
• 2 tablespoons butter (for cooking)
• Sour cream or salsa (for serving, optional)