Cover mini pizzas with slices of plum tomatoes for a fresh take on a family favorite; sprinkle mozzarella cheese on top.
Preheat oven to 400 degrees. Brush 2 baking sheets with oil; set aside. On a lightly floured surface, divide dough into 4 pieces. Roll out each piece into a 6-inch disk about 1/4 inch thick.
Transfer disks to oiled baking sheets. Brush with oil, and sprinkle with salt. Top each disk with a thin layer of tomato slices.
Sprinkle 1/4 cup cheese over each disk. Top each with a few more tomato slices, and sprinkle with another tablespoon cheese. Sprinkle each pizza with 1/2 teaspoon oregano.
Bake until crusts are golden, about 20 minutes. Drizzle pizzas with extra-virgin olive oil before serving, if desired.