1. Combine first 3 ingredients in a microwave-safe 1-quart liquid measuring cup; microwave at HIGH for 4 minutes. Stir to form small curds. Strain through a sieve lined with a double layer of cheesecloth; let stand for 5 minutes. Discard liquid. Scrape cheese mixture into a small bowl; stir in rind and 1/4 teaspoon salt.
2. Cook pasta according to package directions, omitting salt and fat, and drain. Heat a large skillet over medium-high heat. Add olive oil to pan; swirl to coat. Add squash and zucchini to pan; sauté 1 minute. Add 1/4 teaspoon salt, tomatoes, and garlic; sauté 4 minutes. Add broth and pasta to pan, and cook for 2 minutes or until thoroughly heated, tossing to combine. Place 2 cups pasta mixture in each of 4 shallow bowls; sprinkle each serving evenly with remaining 1/2 teaspoon salt and pepper. Top each serving with 2 tablespoons cheese mixture and 1 tablespoon mint. Serve immediately.