Preheat the oven to 230 Celsius. Brush a large baking dish with olive oil. In a large bowl, whisk the egg. Stir in the breadcrumb, garlic, parsley, 1/4 cup of the cheese, 1 teaspoon of salt and 1/2 teaspoon of pepper. Add the ground beef and gently knead to combine. Form the mixture into 2-cm meatballs and transfer to the baking dish. Bake for about 10 minutes, turning once until browned.

Meanwhile, in a large saucepan, heat the 1 tablespoon of olive oil. Add the crushed tomatoes and cook over moderately high heat until bubbling.

Add the meatballs to the tomato sauce, cover partially and simmer over moderately low heat until the meatballs are cooked through about 10 minutes. With a large spoon, mash the meatballs into large chunks. Remove from the heat.

Meanwhile, brush 2 large baking sheets with olive oil and preheat in the upper and lower thirds of the oven. On a lightly floured work surface arrange the dough on the heated baking sheets. Bake for about 7 minutes, shifting the pan halfway through baking, until lightly golden on top.

Spread the meatball sauce over the crust, leaving a 1-cm border around the rim. Sprinkle with the remaining 3/4 cup of cheese. Bake for about 5 minutes, until the crust is crisp on the bottom and the cheese is melted. Scatter basil leaves over the pizza and serve hot.