For the dough: crumble yeast into a bowl and whisk until smooth with 200 ml (approximately 3/4 cup) of lukewarm water and sugar. Add flour, olive oil and salt and knead to a smooth dough. Cover and let rise for about 1 hour in a warm place.
Divide dough into 4 balls and roll out each into about 22 cm (approximately 9 inches) circle, making the edges slightly thicker. Arrange on 2 greased baking sheets or in large pizza pans.
For the topping: blanch tomatoes in hot water briefly, rinse in cold water and peel, dice and season with salt and pepper. Spread tomatoes on pizza dough, leving small edges free. Cut mozzarella into thin slices and arrange on tomatoes, drizzle with a little olive oil.
Bake 2 pizzas in preheated oven at 220°C (approximately 425°F) for about 20 minutes. Remove from the oven and garnish with basil. Bake remaining pizzas in the same manner. Serve.