Whisk the flour, baking powder and salt in a large bowl (or pulse in a food processor).
Stir in the warm water and olive oil; knead about 1 minute on a lightly floured surface until smooth — don't overwork it.
Cover the dough and rest it 10 minutes (the gluten relaxes — the dough rolls without springing back).
Divide into 2 balls; roll each into a long oval, ⅛–¼ inch thick.
Dust 2 baking sheets with cornmeal; transfer the crusts; poke all over with a fork.
Par-bake 5–8 minutes at 475°F until the edges turn golden and the crust is nearly cooked through.
Brush with olive oil; top lightly — ¼ cup sauce + 4 oz mozzarella per crust, basil after the bake.
Bake 5–10 minutes more until the cheese is melty and the crust is golden; slice into 4 wedges per crust and serve immediately.