1. In a medium skillet, warm the olive oil over medium heat. Add the onions and cook, stirring occasionally, until softened and translucent, about 5 minutes. Add all but 2 tablespoons of the corn and cook until tender, about 3 minutes.
2. In a food processor, purée the corn and onion mixture. Transfer to a large bowl and fold in the fromage blanc, Parmigiano-Reggiano, vinegar, tarragon and 1 teaspoon of the chives until combined. Season with salt.
3. Place one pasta sheet on a lightly floured work surface. Using a 3½-inch pastry cutter or drinking glass, cut the dough into circles; discard the scraps. Spoon about 1 teaspoon of the corn filling into the center of each circle. Brush the pasta edges with water, fold the circles in half to create a half moon and seal the edges. Press the two corners together to form the cappelletti. Repeat with the remaining pasta and filling.
4. Bring a large pot of salted water to a boil. Cook the cappelletti until al dente, about 2 minutes. Using a slotted spoon, transfer the cappelletti to a large bowl.
5. In a large skillet, bring ¼ cup of the pasta water and the butter to a simmer over medium heat and cook, whisking, until emulsified and slightly reduced, about 2 minutes. Stir in the remaining 2 tablespoons of corn, the remaining teaspoon of chives and the parsley. Add the cappelletti and toss gently to coat with the sauce. Divide the cappelletti among plates. Garnish with a drizzle of honey and additional cheese, if desired, and serve immediately.