Preheat oven to 375°F.
Spray an 8-inch pie pan with cooking spray. Pour 1 tablespoon of the olive oil into a small bowl and lightly brush each tortilla on both sides. Place the tortillas around the pan to form an overlapping circular crust. Bake 5 minutes, until lightly golden.
Spoon the spinach evenly over the tortillas, then put half the Feta on top. Sprinkle with the chopped tomatoes and top with the remaining Feta. Drizzle with the remaining olive oil and season with the salt and pepper.
Bake 15 to 20 minutes, until the cheese is golden. Let stand for 5 minutes before slicing. Garnish with the basil.