Oil a 26 cm baking pan.
Open the fluffy pizza crust with a rolling pin in a large diameter, so as to cover the base and sides of the baking pan. Do not sprinkle any flour on it.
If the crust is too cold, let it stand at room temperature for a while to soften.
Sprinkle the mozzarella and any other ingredients you want on the base, add 2-3 tbsp sauce, and repeat with the rest of the cheese and other ingredients. Then, cover the surface with thick tomato sauce. Finally, sprinkle with very little extra cheese. Preheat the oven at the highest temperature (220-250 °C).
Bake for approx. 15 min until the fluffy pizza crust turns golden brown.
Let it stand for 15 min and then transfer it onto a platter. Carefully cut the pizza, because the melted cheese and sauce will run out of the pizza core.

For the pizza sauce:
In a saucepan, melt the butter over medium heat, and add the minced onion. Cook for a few minutes until it becomes transparent. Add the garlic, crushed or minced, and the tomato paste, and saute for 1 min, stirring. Add the tomatoes, sugar, herbs, salt and pepper, and bring to a boil. Lower the heat, cover the saucepan and let the sauce simmer for approx. 30 min, until really thick. Finally, add the fresh basil, oregano, salt and pepper and stir.
Leave the sauce aside.