Preheat your oven to 400°F (200°C).
Brush one side of each flour tortilla with olive oil and place them on a baking sheet, oiled side down.
Spread 1/2 cup of refried beans evenly over each tortilla.
Layer the seasoned ground beef over the refried beans on both tortillas.
Sprinkle 1/2 cup of cheddar cheese and 1/2 cup of mozzarella cheese on top of the beef on each tortilla.
Add diced tomatoes, black olives, and green onions evenly over the cheese.
Drizzle taco sauce over the toppings on each pizza.
Place the second tortilla on top of each prepared tortilla stack.
Bake in the preheated oven for 10-12 minutes, or until the cheese is melted and the tortillas are golden brown.
Remove from the oven, let cool for a few minutes, then slice into wedges and serve warm.