In a medium bowl, whisk together the greek yogurt, mayonnaise, and buttermilk until smooth and well combined. Add the olive oil, lemon juice, and apple cider vinegar, whisking until fully incorporated. Stir in the garlic powder, parsley, dill, sugar, salt, black pepper, and smoked paprika. Mix thoroughly to ensure all seasonings are evenly distributed throughout the dressing. Set aside at room temperature while you prepare the other components. I like to make the dressing first so the flavors have time to meld together before tossing with the pasta.
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 the fresh ingredients: halve the cherry tomatoes lengthwise, cut the broccoli into small 1/2-inch florets, dice the red bell pepper into 1/4-inch pieces, and ensure your chicken is shredded or cut into 1/2-inch bite-sized cubes. When the pasta is done, drain it thoroughly and spread it out on a sheet pan or large bowl to cool for 3-5 minutes. This brief cooling prevents the warm pasta from breaking down the creamy dressing.
In a large mixing bowl, combine the cooled pasta, shredded chicken, halved cherry tomatoes, broccoli florets, corn, and diced red bell pepper. Pour most of the creamy greek yogurt dressing over the mixture (reserve a small amount to add before serving) and toss everything together until well coated. I prefer to hold back a bit of dressing initially because as the salad sits in the refrigerator, the pasta continues to absorb moisture, so you can adjust the consistency just before serving.
In a small bowl, combine the crumbled cooked bacon with the feta cheese, mixing gently so the feta stays in nice chunks. Fold this mixture into the dressed pasta salad, being careful not to crush the feta. The bacon adds a wonderful smoky contrast to the creamy dressing, and keeping it separate until the end ensures it stays crispy rather than getting soggy.
Transfer the assembled salad to a serving bowl or storage container and refrigerate for at least 1 hour before serving. This allows the flavors to meld beautifully and the pasta to fully absorb the dressing. Just before serving, stir in the reserved dressing from Step 1 to refresh the creaminess and ensure a perfect consistency.