Cook the elbow macaroni according to package instructions until al dente. Drain and rinse under cold water to cool.

In a large pot of boiling water, blanch the broccoli florets for 2-3 minutes until bright green and tender-crisp. Drain and immediately transfer to a bowl of ice water to stop cooking. Drain again and set aside.

In a large mixing bowl, combine the mayonnaise, sour cream, apple cider vinegar, Dijon mustard, garlic powder, onion powder, salt, and pepper. Whisk until smooth.

Add the cooled macaroni, broccoli, cheddar cheese, cherry tomatoes, and red onion to the bowl. Gently toss until everything is well coated with the dressing.

Cover and refrigerate for at least 1 hour to allow the flavors to meld.

Before serving, taste and adjust seasoning if necessary. Serve chilled or at room temperature.