Combine the passata, basil, garlic and oil in a bowl. Season with salt, cover and leave to infuse for 15 minutes.
Heat a baking sheet in a preheated oven, 240°C (475°F), Gas Mark 9. Place 1 pizza dough ball on the base only of a well-floured, 23 cm (9 inch) loose-bottomed tart tin. Push down on the dough with your fingertips, pressing it out to fill the base, leaving the border slightly thicker. If you get any tears, forcefully pinch the dough around the hole back together.
Spoon 3 tablespoons of the passata mix over the base and scatter with a quarter of the mozzarella. Brush the border with oil to glaze. Remove the heated baking sheet from the oven, slide the tin on to it, then quickly return to the oven. Bake for 7–8 minutes until crisp and risen. Top with 3 slices of speck, then half the dolcelatte. Serve immediately, garnished with a little torn basil. As the first pizza cooks, prepare the next for the oven.