Preheat the oven to 375 degrees Fahrenheit.

Lay 2 of the flour tortillas into the bottom of a 9x13 baking dish. Use a knife to trim excess edges to fit the dish.

Spray a 9x13 baking dish with nonstick spray and set aside.

In a skillet over medium-high heat, cook ground beef, onion, and garlic until beef is browned and cooked through. Drain excess fat.

In a small bowl, whisk together taco seasoning and water. Pour over cooked beef mixture and simmer for 2-3 minutes until thickened.

Arrange 2 of the tortillas in the prepared dish. Spread half of the beef mixture evenly over the tortillas.

Spread half of the salsa over the beef layer.

Sprinkle 1.5 cups of shredded cheese over the salsa.

Layer remaining tortillas, beef mixture, salsa, and cheese in the same order for a second layer.

Bake in the preheated oven for 20-25 minutes until bubbly and golden. Garnish with cilantro, and serve with sour cream and pico de gallo if desired.