Begin by bringing a large pot of salted water to a rolling boil. Add the rigatoni and cook according to the package instructions, usually about 10-12 minutes, until al dente. Once cooked, drain the pasta in a colander and rinse it under cold water.

In a small mixing bowl, whisk together the olive oil, lemon juice, honey, and Dijon mustard. Season with salt and black pepper to taste.

In a large mixing bowl, add the cooled rigatoni, crumbled feta, dried cranberries, chopped walnuts, baby spinach, and sliced red onion. Mix gently.

Drizzle the lemon vinaigrette over the mixed salad ingredients and toss lightly to coat without breaking the pasta.

Serve immediately or cover and refrigerate for about 15 minutes to allow flavors to meld.