Preheat the oven to 350° and butter a 9-by-13-inch ceramic baking dish. In a medium bowl, toss the crabmeat with the parsley, chives, lemon juice and cayenne. Season with salt and black pepper.
Butter each baguette slice and stand up the slices in the prepared baking dish. Using a spoon, tuck the crab mixture evenly between the slices of bread.
In a bowl, whisk the eggs with the milk, half-and-half, 1 teaspoon of salt and 1/2 teaspoon of black pepper. Pour the custard evenly over the bread and let stand for 10 minutes.
Bake the bread pudding for 30 minutes, until the top is lightly browned and the custard is set. Let stand for 10 minutes before serving.