Preheat the Oven: Preheat the oven to 450°F, placing a pizza stone or large sheet tray on a rack positioned at the top of the oven while it heats.
Prepare the Pita Bases: Brush each 5-inch pita evenly with about 1 teaspoon of the olive oil, covering the surface without oversaturating it.
Add the Tomato Sauce: Spread about 2 tablespoons of tomato sauce over each pita, keeping approximately a 1/2-inch border around the edge.
Top with Mozzarella: Divide the 4 ounces of torn fresh mozzarella among the pitas, using about 1 ounce per pizza and distributing it evenly over the sauce.
Season the Pitas: Lightly sprinkle each assembled pita with flaky salt if desired.
Transfer to the Oven: Carefully use a heat-safe spatula to move the prepared pitas directly onto the preheated pizza stone or sheet tray.
Bake the Pita Pizzas: Bake for 6 to 7 minutes, until the mozzarella is melted and the pita breads are crispy.
Finish with Basil: Allow the baked pita pizzas to cool briefly, then scatter the torn fresh basil leaves over the tops.
Slice and Serve: Slice the pita pizzas and serve while fresh.