Chilled Creamy Tomato-Basil Soup

3 tablespoons extra virgin olive oil
2 large yellow onions, roughly chopped
2 medium carrots, peeled and sliced into 1/4-inch rounds
5 cloves garlic, smashed and peeled
2 (26 oz) boxes Pomi chopped tomatoes or 2 (28 oz) cans crushed or diced tomatoes
4 cups water
1-1/2 cups orange juice, preferably not from concentrate
1/4 cup sugar
2-1/2 teaspoons salt
10 leaves fresh basil, plus more for garnishing soup
1/3 cup heavy cream

Heat the olive oil in a large pot over medium heat. Add the onions, carrots and garlic and cook, stirring occasionally, until vegetables are soft and just beginning to brown, about 15 minutes.
Add the tomatoes, water, orange juice, sugar, salt and basil and bring the soup to a boil. Turn heat down to low, cover and simmer for about 25 minutes.
Purée the soup with a hand-held immersion blender until completely smooth. (Alternatively, use a standard blender to purée soup in batches. Always be careful not to fill the jar more than halfway, and leave the hole in the lid open and loosely cover with a dish towel to allow the heat to escape.) Stir in the heavy cream. Taste and adjust seasoning with salt and/or sugar if necessary.
Transfer the soup to a container (or leave in the pot if you wish) and refrigerate until very cold.
Ladle the soup into bowls and top with fresh chopped basil. Garnish with whole basil leaves if desired.