In a large bowl, combine bread flour, semolina flour, and yeast. Gradually add room temperature water while mixing. Once the dough begins to form and stiffen, add the olive oil in a thin stream, then add the salt. Cover and rest for 10 minutes.
2
Fold the dough several times, cover with plastic wrap, and let it rise for 2 hours or until doubled in size.
3
While the dough rises, prepare the topping. Thinly slice the onions. In a pot, melt the anchovies in olive oil. Add the onions and sauté over high heat until golden. Season with salt, add the hand-crushed tomatoes and a glass of water.
4
Reduce heat and simmer gently for about 30 minutes, stirring occasionally, until the sauce becomes thick and flavorful. Allow to cool completely.
5
Meanwhile, grate the caciocavallo cheese. In a skillet, lightly toast the breadcrumbs in olive oil, stirring frequently, until golden but not overly browned (they will darken further in the oven).
6
Lightly oil a 25×35 cm (10×14 inch) baking tray. Transfer the dough to the tray and gently stretch it with your fingers from underneath. Don't force it—let it rest and stretch gradually. Once spread, cover and let rise for another 30 minutes (up to 1 hour if the room is cool).
7
Preheat oven to 220°C (430°F). Top the dough in this order: anchovies (whole or chopped), grated caciocavallo cheese, tomato-onion sauce spread generously to the edges, a drizzle of raw olive oil, plenty of oregano, more cheese, and toasted breadcrumbs.
8
Bake in a static oven for 30–35 minutes. Serve warm.