Place the tomatoes and their juices in a food processor and process until finely chopped but not liquified. Transfer to a heavy saucepan. Stir in the tomato puree and place over low heat. Bring to a simmer and cook, stirring often, until the sauce is hot and slightly thickened, about 20 minutes. Season with salt and pepper.
If desired, stir in the butter, olive oil, or sugar to balance