Preheat the oven to 350°F (175°C). Lightly grease a deep 9x13-inch baking pan and set aside.
Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add the chopped onion and cook about 2 minutes until softened.
Add the ground beef to the skillet and cook, breaking it up, until no longer pink; drain excess grease.
Return the skillet to medium heat. Stir in the minced garlic, chili powder, cumin, smoked paprika, dried oregano, 1 teaspoon salt, and tomato paste; cook 1 minute to bloom the spices.
Stir in the refried beans, 1½ cups salsa, ½ cup water, and the chopped green chilies. Cook and stir until the mixture is smooth and fully combined. Taste and add cayenne pepper if desired. Remove from heat and set aside.
Make the creamy filling: in a medium bowl whisk together 1½ cups sour cream, 4 oz. softened cream cheese, ½ cup salsa verde, and a pinch of salt until smooth; set aside.
Combine the two cheeses in a bowl and set aside.
Optional: char the tortillas briefly over a gas flame or in a dry cast-iron skillet until lightly charred in spots.
To assemble: spread ½ cup of salsa in the bottom of the prepared baking dish in a thin even layer.
Arrange tortillas to cover the layer: place 2 whole tortillas in the center and surround with 6 tortilla halves (see photo layout) so the layer is covered.
Spread one-third of the creamy filling over the tortillas, sprinkle with 1 cup of the combined cheeses, then spread one-third of the meat mixture over the cheese.
Repeat two more times: tortillas, one-third creamy filling, 1 cup cheese, and one-third meat mixture to use up all filling and meat.
Top with a final layer of tortillas, spread the remaining salsa over the top, and sprinkle with the remaining cheese.
Cover the dish and bake 30–40 minutes until cheese is melted and the casserole is heated through. Let rest 10 minutes before cutting.
Serve with lettuce, tomatoes, olives, avocado slices, cilantro, jalapenos, sour cream, and crushed Nacho Cheese Doritos as desired.