Southwestern Pasta Salad

8 ounces campanelle or other short pasta

1 teaspoon kosher salt, divided, plus more for pasta water

¾ cup olive oil

½ cup loosely packed fresh cilantro leaves and tender stems

¼ cup fresh lime juice (from about 2 limes)

1 ripe avocado, halved, divided

½ teaspoon black pepper, divided

1 15.5-oz. can black beans, rinsed and drained

1 pint cherry tomatoes, halved

1 cup fresh corn kernels (from about 3 ears) or 1 frozen corn, thawed

5 scallions, thinly sliced

Cook pasta in a large pot of boiling salted water until al dente, 8 to 10 minutes; drain and rinse pasta under cold water to cool. Meanwhile, combine olive oil, cilantro, lime juice, ½ of the avocado, ½ teaspoon of the salt, ¼ teaspoon of the pepper and ¼ cup of water in a blender and process until smooth, scraping down sides as needed. Combine pasta and avocado dressing in a large bowl and toss to combine. Add beans, tomatoes, corn, and remaining ½ teaspoon salt and ¼ teaspoon pepper; toss well. Thinly slice remaining half of avocado. Serve salad topped with scallions and avocado