Bring a large pot of salted water to a rapid boil. Add the pappardelle and cook for about 9 minutes until al dente. Reserve ½ cup pasta water, then drain and set aside.

In a large skillet, heat 2 tablespoons of olive oil over medium-high heat. Sauté sliced red onion for about 2 minutes until translucent. Add corn, season with salt and pepper, and sauté for another 3 minutes until tender and golden.

Transfer the onion and corn mixture to a blender. Add mascarpone, basil, and ¼ cup of water. Blend until smooth. Taste and adjust seasoning, then set aside.

In the same skillet, add remaining olive oil and heat. Add cherry tomatoes and cook for about 6-8 minutes until blistered. Stir occasionally for even cooking.

Reduce heat to medium, add drained pappardelle and basil cream sauce to the skillet. Toss gently to combine, adding reserved pasta water if necessary for desired consistency.

Divide among serving bowls. Drizzle with olive oil, sprinkle with Parmigiano Reggiano, flaky sea salt, and black pepper. Garnish with additional basil leaves if desired.