In a heavy large skillet, heat 1/2 cup sugar over medium-high heat until sugar begins to melt, shaking skillet occasionally to heat sugar evenly. Do not stir. Once the sugar starts to melt, reduce heat to low and cook about 5 minutes more or until all of the sugar is melted and golden, stirring as needed with a wooden spoon.
Remove skillet from heat and immediately divide the caramelized sugar among six 6-ounce ramekins, or soufflé or custard dishes. Working quickly, rotate ramekins so sugar coats the bottom as evenly as possible. Cool the caramelized sugar.
In a medium saucepan, heat whipping cream, whole milk and 1/3 cup sugar over medium-low heat, stirring occasionally, for 15 minutes or until tiny bubbles just form around the edge.
Meanwhile, in a large bowl, whisk eggs and egg yolks until mixed. Slowly whisk the hot whipping cream mixture into the egg mixture. Stir in bourbon, brandy, rum and nutmeg.
Place the prepared ramekins in a shallow roasting pan. Pour egg mixture into the ramekins. Pour hot tap water into the roasting pan around the ramekins to a depth of about 1/2 inch.
Bake in a 325 degree F oven for 30 to 35 minutes or until a knife inserted near center comes out clean. Cool 1 hour. Cover and chill for 2 to 24 hours.
To serve, unmold the custards by loosening the edges with a knife. Slip the end of knife down the sides of ramekin to let in air. Carefully invert a dessert plate over a ramekin; turn dishes over together to release custard. Spoon any of the caramelized sugar that remains in ramekin on top. Makes 6 servings.