Bring a large pot of salted water to a boil over high heat. Add the penne pasta and cook according to the package instructions until it is al dente. It is important not to overcook the pasta so it maintains its shape when tossed with the other ingredients. Once finished, drain the pasta and rinse it briefly under cool water to stop the cooking process and remove excess starch.
In a small glass jar or a medium mixing bowl, combine the extra virgin olive oil, apple cider vinegar, honey, salt, and black pepper. Whisk the ingredients vigorously until the honey is fully dissolved and the oil and vinegar have emulsified into a smooth dressing. Taste and adjust the seasoning if you prefer a bit more sweetness or a sharper tang.
In a large serving bowl, add the cooled penne pasta, dried cranberries, chopped baby spinach, and finely diced red onions. Pour the dressing over the top and toss gently to ensure every piece of pasta is coated. The warmth of the pasta, even after rinsing, will help the spinach wilt just slightly, making it easier to eat.
Gently fold in the crumbled feta cheese and the toasted walnuts. Doing this at the end prevents the feta from breaking down too much and keeps the walnuts crunchy. Transfer the salad to a festive serving dish if you are preparing for a Christmas dinner, or serve it directly from the bowl for a casual meal.
