1Preheat your oven to 400°F and position the rack in the center. Place a large baking sheet inside while preheating for extra crispiness.
2Heat 1 tablespoon oil in a large skillet over medium-high heat until shimmering, about 1 minute. Add the diced onion and cook until softened and translucent, about 3-4 minutes, stirring occasionally.
3Add minced garlic to the skillet and sauté until fragrant, about 30 seconds. Add ground beef, breaking it apart with a wooden spoon. Cook until browned completely with no pink remaining, about 6-8 minutes.
4Drain excess fat from the beef, leaving just enough to keep the meat moist. Stir in taco seasoning and 2-3 tablespoons water. Simmer until the liquid reduces and the meat is well-coated, about 2 minutes. Remove from heat.
5Warm refried beans in a small saucepan over low heat or in the microwave until spreadable, about 1-2 minutes.
6Remove the preheated baking sheet from the oven carefully. Brush the remaining oil lightly on the hot sheet. Place 2 tortillas on the sheet as your base layer.
7Spread ½ cup of warmed refried beans evenly on each base tortilla, leaving a ¼-inch border around the edges. This creates a moisture barrier.
8Distribute the seasoned ground beef evenly over the beans on both tortillas, using about half the beef mixture per pizza.
9Sprinkle 1 cup of shredded cheese over the meat layer, dividing equally between both pizzas.
10Place the remaining 2 tortillas on top of each stack, pressing down gently to seal the layers together.
11Spread a thin layer of salsa (about 3 tablespoons) on top of each upper tortilla. Sprinkle the remaining 1 cup of cheese over the salsa.
12Bake in the preheated oven until the cheese melts completely and bubbles, and the tortilla edges turn golden and crispy, about 10-12 minutes.
13Remove from oven and let rest for 2-3 minutes to allow the cheese to set slightly for easier cutting.
14Top each Mexican pizza with dollops of sour cream, sliced black olives, jalapeño slices, sliced scallions, and fresh cilantro.
15Slice each pizza into 4 wedges using a sharp pizza cutter or knife. Serve immediately while hot and crispy.