Preheat the oven to 350 degrees F. Slice the corn kernels from the ear in a large, deep bowl with a sharp knife. Turn the knife to the dull side and scrape the cob all the way down to remove all the bits of kernel and the creamy milk.
Add the red bell peppers, jalapenos, heavy cream, 2 teaspoons salt, a generous amount of pepper and the butter and mix well. Pour into a 9-by-13-inch baking dish. Bake until hot and bubbly, 45 to 55 minutes.