Bring a large pot of salted water to a boil and cook the pasta according to package directions until al dente. While the pasta cooks, prepare all your ingredients: slice the red onion into thin half-moons, cut the green onions into 1/2-inch pieces, chiffonade the basil into thin ribbons, and measure out the almonds, cranberries, and feta. When the pasta is done, drain it in a colander and rinse thoroughly with cold water to stop the cooking process and cool it completely—this prevents the salad from becoming warm and wilted.
In a medium bowl, whisk together the mayonnaise, apple cider vinegar, lemon juice, honey, olive oil, poppy seeds, salt, and black pepper until smooth and well combined. I like to taste the dressing as I mix it—the balance between the tanginess of vinegar and the sweetness of honey is key to making this salad sing. Set the dressing aside until you're ready to toss everything together.
In a large bowl, combine the cooled pasta from Step 1 with the spinach, shredded or cubed chicken, berries, prepared red onion, almonds, cranberries, and most of the basil ribbons (reserve some for garnish). Toss gently to distribute all the ingredients evenly. I recommend saving some of the delicate items like berries for gentle handling—add them last and fold them in carefully to avoid crushing them.
Pour the dressing from Step 2 over the assembled salad and toss everything together until evenly coated. Top with the reserved basil ribbons, fresh lemon zest, feta cheese, and green onions for brightness and visual appeal. Serve immediately, or chill until ready to serve—this salad is best enjoyed within a few hours while the flavors are fresh and the texture is at its peak.