Bring a large pot of salted water to a boil. Add the rigatoni and cook until al dente, about 8-10 minutes. Drain and rinse under cold water to stop the cooking.

In a spacious mixing bowl, combine the cooled rigatoni, chopped spinach, halved cherry tomatoes, crumbled feta, dried cranberries, and finely chopped red onion. Stir gently to mix everything together.

In a small bowl, whisk together olive oil, lemon juice, Dijon mustard, garlic powder, salt, and pepper until the mixture is well emulsified and smooth.

Pour the dressing over the salad mixture and gently toss everything together until the pasta and vegetables are evenly coated with the flavorful dressing.

Cover the salad and place it in the refrigerator for at least 30 minutes to let the flavors meld. Enjoy chilled as a delightful light meal or side dish!