In a medium bowl or the bowl of your electric mixer combine eggs, yolks and sugar, whisk to combine.
Place your mixing bowl over a pan of hot water over low heat and stir continuously until it reaches 165°F.
I like to start the water off at well below the boiling point and slowly raise the temperature until it's just shy of boiling.
Do not whisk this mixture too much at this stage or you will incorporate too much air and take too long to heat.
If water starts to boil or you see steam coming off your mixture remove from the heat for a few seconds and whisk.
Getting this mixture too hot will cause eggs to cook.
After desired temperature is reached, use the whip attachment for your electric mixer and beat on high speed until thick and cooled to just warm to the touch.
Beat in vanilla and optional bourbon, serve ASAP.
The mixture will keep in the fridge for a day or so before it starts to separate.
Variations: Use rum, flavored liqueur or various extracts in lieu of bourbon.