Cook the Pasta: Bring a large pot of salted water to a boil, add rotini pasta and cook al dente according to package directions, then drain and rinse with cold water until completely cooled.
Prepare Vegetables: While pasta cooks, dice avocado, quarter cherry tomatoes, finely dice red onion, chop cilantro, and seed and dice jalapeño pepper for uniform bite-sized pieces throughout salad.
Combine Salad: Transfer cooled pasta to a large bowl, then gently fold in avocado, black beans, corn, tomatoes, onion, cilantro, and jalapeño until evenly distributed without mashing delicate avocado pieces.
Make Dressing: In a medium bowl, whisk together mayonnaise, sour cream, milk, lime juice, garlic powder, onion powder, chipotle powder, and salt until a smooth and creamy consistency forms.
Dress and Chill: Pour creamy dressing over pasta mixture, toss gently until everything is evenly coated, then cover and refrigerate for at least thirty minutes before serving.
Serve: Before serving, garnish with additional chopped cilantro for fresh color and flavor, then serve chilled as a perfect side dish for summer gatherings and potlucks.