Scrape the corn from the cob by balancing the cob on small inverted bowl nested in larger bowl. Using a sharp knife, cut the kernels off the cob from the top to the bottom.
Heat the extra-virgin olive oil, a turn of the pan, in a sauce pot over medium-high heat. Add the corn and saute until it starts to brown at the edges, 3 to 4 minutes. Add the scallions and cook for 1 minute, then add the stock and bring to a boil. Whisk in the polenta and cook until thick, about 2 to 3 minutes. Stir in the butter and season with hot sauce and salt, to taste. Transfer to a serving bowl and serve.