There are several recipes I use that call for only yolk. This one, though, is by FAR my favorite.
Creme Brulee (food network's version)
1 quart heavy cream
1 vanilla bean, split and scraped (they are SO expensive, but make all the difference)
1 cup vanilla sugar, divided in half (you can make vanilla sugar by simply adding vanilla extract to the sugar)
6 large egg yolks
2 quarts hot water
Preheat the oven to 325 degrees F.
Place the cream, vanilla bean and its pulp into a medium saucepan set over medium-high heat and bring to a boil. Remove from the heat, cover and allow to sit for 15 minutes. Remove the vanilla bean and reserve for another use.
In a medium bowl, whisk together 1/2 cup sugar and the egg yolks until well blended and it just starts to lighten in color. Add the cream a little at a time, stirring continually. Pour the liquid into 6 (7 to 8-ounce) ramekins. Place the ramekins into a large cake pan or roasting pan. Pour enough hot water into the pan to come halfway up the sides of the ramekins. Bake just until the creme brulee is set, but still trembling in the center, approximately 40 to 45 minutes. Remove the ramekins from the roasting pan and refrigerate for at least 2 hours and up to 3 days.
Remove the creme brulee from the refrigerator and let sit for at least 30 minutes. Divide the remaining 1/2 cup vanilla sugar equally among the 6 dishes and spread evenly on top. Using a torch*, melt the sugar and form a crispy top. Allow the creme brulee to sit for at least 5 minutes before serving.
*if you don't have a torch (like me) you can use your broiler setting on the oven to brown the tops. Just make sure to watch closely--the last thing you want is burnt brulee...even though "brulee" means burnt!