1. Heat oven to 325 degrees F. Place six 4- to 6-ounce ramekins in a 13 x 9 x 2-inch roasting pan.
2. With tip of sharp paring knife, slit open vanilla bean and scrape out seeds. Place seeds in a small, heavy-bottomed saucepan with half- and-half, saving bean for another use. Heat just until small bubbles appear at the edge of the pan. Remove from heat.
3. In a medium-size bowl, whisk together eggs, egg yolks, and sugar. Whisk a small amount of warm half-and-half into egg mixture. Whisk egg mixture back into half-and-half in saucepan. Return to medium-low heat and cook 7 to 8 minutes, stirring, until mixture coats the back of a spoon.
4. Divide mixture evenly among ramekins. Place baking pan in oven. Pour hot water halfway up sides of ramekins. Bake at 325 degrees F for 18 to 22 minutes or until custard is set but still jiggly in centers. Remove ramekins from baking pan; cool completely. Refrigerate until just before serving.To serve:
5. Remove ramekins from refrigerator. Heat broiler. Sprinkle each ramekin with 2 teaspoons turbinado sugar. Run under broiler for 2 to 3 minutes (depending on your oven); watch carefully so as not to burn sugar. Cool slightly and serve.