Preheat the oven to 200°C (400°F). Prick the back of the chicken wings with a sharp knife and pat them dry with paper towels. Arrange the wings on a baking pan lined with parchment paper and sprinkle evenly with salt. Bake for 25 minutes, or until lightly browned and cooked through.
Meanwhile, use a vegetable peeler to remove 4 strips of lime zest and cut the lime in half. Squeeze 2 tablespoons of fresh lime juice into a saucepan. Chop the scallion in half and add the white bottom part to the saucepan, reserving the green part. Finely chop the green part and set aside. Add the lime zest, cola, soy sauce, garlic, and ginger to the saucepan.
Bring the cola mixture to a boil, then reduce the heat and simmer, uncovered, for 20 minutes, or until the sauce thickens and reduces by about half. Drain out the solids. In a small bowl, whisk together the cornstarch with 1 tablespoon of water. Stir this mixture into the cola sauce and cook for an additional 3 minutes. Turn off the heat. Pour half of the sauce into a large bowl and mix well with butter. Reserve the remaining sauce for serving.
Remove the chicken wings from the oven and toss them in the cola mixture. Return the wings to the baking pan and bake for an additional 5 minutes, or until they are dark golden brown and glossy.
Serve the chicken wings immediately with the Coca-Cola sauce. Garnish with chopped scallions and a sprinkle of white sesame seeds on top