Melt the butter in a large heavy skillet over medium heat. Add the shallots; cook 1 minute. Add the cream and quarter cup basil. Heat to boiling; reduce the heat. Simmer, stirring occasionally, until thick, about 10 minutes. Add the lemon juice, vinegar, hot pepper sauce, and salt and pepper to taste. Stir in the zucchini and toss it until well coated. Add the tomatoes; toss lightly. Sprinkle with the remaining 1 TB basil. Serve immediately.