Look for large tomatoes, as they're easier to work with. If you make the soup ahead, the flavors will meld with time, but give the soup a quick stir before serving. Cheesy toasts add a bit of extra protein to this end-of-summer soup.
Core tomatoes, and halve crosswise. Working with 1 tomato at a time, squeeze tomato halves over a sieve over a bowl; press sieve gently with the back of a wooden spoon to extract remaining juice, reserving tomato halves and juice. Discard seeds.
Press tomato halves through large holes of a box grater into a large bowl; discard skins. Add reserved tomato juice to bowl. Stir in 2 tablespoons chopped mint, 1/2 teaspoon salt, and vinegar.
Place garlic in a food processor; process until chopped. Add 1/2 cup mint leaves and 1/8 teaspoon salt; process until pureed. With the motor running, gradually pour oil through food chute, processing until oil is fully incorporated, scraping sides as necessary.
Slice bread crosswise into 8 slices. Spread cream cheese evenly over 1 side of bread slices. Place bread, cheese side up, in a single layer on a baking sheet. Broil 2 minutes or until golden. Ladle about 1 cup soup into each of 4 bowls; divide pesto evenly among bowls. Serve with toasts.