To prepare the soup:
In a sauté pan, cook the oil over medium heat until it is hot, about 1 minute. Add the shallots and cook, stirring well, for 3 minutes. Add the corn kernels and continue to cook for 3 more minutes, stirring well. Increase the heat to high, add the sherry, and cook for 2 more minutes, stirring well. Add the stock and bring the soup to a boil. Cover the pan, reduce the heat to simmer, and cook for 30 minutes. Let the soup cool, then place in a food processor and process for 2 minutes. Strain the soup into a clean saucepan, add the cream and sugar, and bring to a boil over high heat. Reduce the heat to simmer and cook uncovered for 20 minutes, stirring every 5 minutes. Adjust salt and pepper to taste.
While the soup is cooking, prepare the crab mixture.
To prepare the crab mixture:
In a sauté pan, cook the butter over medium-high heat for 1 minute until it is hot. Add the red bell pepper and chives; cook, stirring well, for 1 more minute. Add the crabmeat, increase the heat to high, and cook for 1 more minute. Add the brandy (being careful, as it might flame) and stir well. Cook for 1 more minute, then turn off the heat. Cover and keep warm.
Pour the soup into 4 bowls and drizzle with the truffle oil. Top each bowl of soup with a quarter of the crab mixture, and serve.
For a smoother soup, strain it a second time before serving it.