Roll out the pizza dough to 1/4-inch thick. Using a 2 to 2 1/2-inch diameter cookie cutter, cut out 18 circles from the dough. Arrange the circles on a heavy large baking sheet. Sprinkle the Gorgonzola cheese over the circles. Top with the tomatoes, pressing them gently into the dough. Bake until the pizzettes are golden brown, about 10 minutes. Drizzle the pizzettes with oil. Sprinkle the basil over the pizzettes. Sprinkle with salt and pepper. Arrange the pizzettes on a platter and serve immediately.