Bring a large pot of salted water to a boil. Add the penne and cook according to package instructions until al dente, about 8-10 minutes. Drain, rinse under cold water to cool, and set aside.

In a small mixing bowl, whisk together the fresh orange juice, olive oil, honey, Dijon mustard, salt, and black pepper until well combined and smooth.

In a large mixing bowl, combine the cooked penne pasta, crumbled feta cheese, dried cranberries, chopped toasted walnuts, baby spinach, and thinly sliced red onion.

Drizzle the freshly made orange vinaigrette over the salad mixture. Gently toss to coat all the ingredients evenly.