1. Start the pizza dough the night before you want to make the pizza; the dough can also sit in the fridge for a few days or be frozen.
2. First make the ferment: roughly mix 100g of the flour with 60g water and leave to stand for between 10 and 50 minutes. Add a third of the yeast and a pinch of the salt and knead in a standing mixer with dough hook attachment or knead by hand for at least 5 minutes until smooth and elastic. Wrap it loosely in cling film and refrigerate for 12-16 hours.
3. To make the main dough, mix the remaining flour with the rest of the water and the malt extract, and again leave for between 10 and 50 minutes. Add the rest of the yeast and salt and knead until smooth and elastic. Add the ferment and knead for 5 more minutes until it comes together in a smooth ball.
4. Divide the dough in four. Shape each piece into a tight ball, place them on a lightly oiled tray, cover with oiled cling film and leave in a warm place for 2 hours, until they double in size. You can refrigerate or freeze them at this point, but make sure they come back to room temperature and have a couple of hours to proof before baking pizza.
5. Preheat the oven grill to maximum setting. Heat up a cast iron griddle or pancake pan, or a heavy large frying pan at least 26cm (10in) in diameter.
6. Flatten each dough ball with your hand and stretch it as thinly as possible without tearing, turning it 90 degrees every now and then on a lightly floured surface. If you struggle to stretch the dough by hand, use a rolling pin. It needn’t be perfect shape or very even thickness. Brush it with olive oil.
7. When the pan is smoking hot, transfer the pizza onto it and drizzle with more olive oil; if some leaks onto the pan, it’s fine - it will make extra crisp patches.
8. Sprinkle with salt flakes and immediately transfer the pan under the preheated grill. Cook for about 3 minutes until golden and lightly charred in places.
9. Slide the pizza onto a board or plate, arrange the provolone slices on it, followed by rolled strips of prosciutto, a sprinkle of Parmesan and basil leaves. Cut into halves or quarters and eat with your hands, folding each slice in half like a sandwich.