In a medium bowl, whisk together the milk, eggs, 1/4 cup of the sugar, vanilla, nutmeg and salt. Pour the mixture over the bread. Let the bread soak for 15 minutes, turning frequently.
Sprinkle the remaining 2 tablespoons sugar over the bread. Arrange the baking dish in a large roasting pan and place in the oven. Pour enough boiling water into the roasting pan to go halfway up the sides of the baking dish. Reduce the heat to 325û and bake for approximately 50 minutes, or until just set.
Melt the butter in a medium saucepan. Whisk together the sugar and the egg in a small bowl. Add the sugar mixture to the butter and cook, whisking constantly, for about 10 minutes, or until thickened.
Remove the pan from the heat and add the bourbon; let cool to room temperature. Serve the sauce with the warm bread pudding.