Boil 8 ounces dried spaghetti in pot of boiling water according to package instructions (or until al dente, about 9 minutes).
Drain and rinse in a colander under cool running water. Transfer 1 1/2 cups of the noodles to a medium bowl; cover and refrigerate remaining noodles (for Noodle Mini Quiches).
Add a handful of halved cherry tomatoes (about 14 or 2/3 cup) and about 2/3 cup cubes low-moisture mozzarella cheese to the bowl with the pasta. Add 2 tablespoons olive oil vinaigrette or purchased Italian dressing, season with salt and pepper, and toss to blend.