Bring a large pot of salted water to a rolling boil. Carefully add the pappardelle pasta and cook until al dente, about 9 minutes. Reserve ½ cup of the starchy cooking water, then drain the pasta.

In a large skillet over medium heat, drizzle 2 tablespoons of olive oil. Sauté chopped red onion for about 2 minutes until translucent. Stir in fresh corn, seasoning with salt and pepper, and cook for 3 minutes until tender.

Transfer the sautéed onions and corn to a blender. Add mascarpone cheese and fresh basil. Blend until smooth and creamy, scraping down sides as needed. Adjust seasoning with salt, pepper, or water.

In the same skillet, add another tablespoon of olive oil and increase heat to medium-high. Add halved cherry tomatoes and cook for 6 to 8 minutes until blistered.

Reduce heat to medium, add drained pappardelle to the skillet with tomatoes. Pour the basil cream sauce over the pasta, stirring gently to coat. If the sauce is too thick, gradually add reserved pasta water until desired consistency.

Plate the creamy pappardelle immediately. Drizzle with olive oil, garnish with additional grated Parmigiano Reggiano, sliced basil, cracked black pepper, and flaky sea salt.