Lightly coat 2 baking sheets with vegetable spray and place 3 tortillas on each. Heat in the oven for 5 minutes. Flip, and bake for another 5 minutes. They should be slightly golden and crispy. Remove them from the oven and set aside.
Meanwhile, cook the ground beef over medium high heat in a large skillet. Drain excess grease and mix in taco seasoning and water. Bring it to the boil and then reduce the heat to medium low. Simmer for 10 additional minutes, stirring occasionally and then remove from heat.
Heat the refried beans in a microwave safe bowl for 30-60 seconds, until they’re heated through but not too hot. Spread a thin layer across the top of 3 tortillas.
Distribute the taco meat evenly across the top of the same tortillas and then top with the 3 remaining bare tortillas. Spread the enchilada or pizza sauce on the top of each one and then top each with cheese, black olives, and tomatoes.
Place pizzas back on a baking sheet and bake for 10 minutes, or until cheese is melted and warm. Let it stand for 5 minutes, slice, and enjoy!