Preheat oven to 230°C/Gas 8.
In a small saucepan, bring 240ml water and white wine vinegar to a simmer. Remove from heat and add mushrooms. Cover and let mushrooms sit, 15 minutes. Strain.
Slice bread horizontally to create two pizzas. Lightly oil a baking tray and place pizzas crust side up. Brush top with three tablespoons of oil.
In a bowl, squeeze tomatoes to break them up slightly. Place on pizza halves. Pull pieces of Buffalo mozzarella from the ball and place on halves. Top with porcini mushrooms, shredded mozzarella, garlic and pepperoni.
Bake until cheese has melted and crust is crispy, about 25 minutes.
Remove pizzas from oven, drizzle with oil, sprinkle with Parmesan and spread with cut basil.
Sprinkle with salt and pepper and serve.