Whisk the eggs with the granulated sugar until well blended.
Incorporate the half-and-half and heavy cream.
Split the vanilla bean lengthwise and scrape the seeds into the mixture along with the vanilla pod. Refrigerate overnight.
Preheat oven to 250 degrees. Remove the vanilla bean pod, stir the mixture, and pour into 8 individual 6-ounce ramekins placed in a baking pan.
Add warm water to the baking pan so it reaches one third of the way up the ramekins. Cover with another pan and bake for 90 minutes, or until the custard is set but still jiggly in the center.
Remove from oven, take the custard out of the water bath, and cool to room temperature. Wrap in plastic and chill.
When ready to serve, preheat oven to broil. Sprinkle a heaping tablespoon of brown sugar on top of each brulée and pat down evenly.
Place the ramekins on a baking sheet under the broiler until the sugar has melted. This takes 1 to 2 minutes and the sugar easily burns, so watch the brûlées constantly (if the sugar burns, scrape it off and try again).
Let the sugar cool and garnish the custards, if desired, with fresh raspberries and sprigs of mint. Serves 8.