Reduce oven temperature to 120°C. Boil 1 litre of water in a kettle.
In a small bowl, combine vanilla extract, eggs, egg yolks and heavy cream and set aside.
Mix cream cheese and sugar in a mixing bowl on low speed for 1 minute. Stop to scrape the side of the bowl. Add sour cream and continue mixing on low speed for another 30 seconds. Stop and scrape for a second time, and continue mixing on low speed for another 1 minute.
While the mixer is running, slowly pour the egg mixture. Stop and scrape 2 to 3 times. Stop mixing when the color of the mixture looks uniform. Pour filling into the cooled crust.
Line the roasting pan with a kitchen towel. Place the springform pan that has been lined with aluminium foil in the roasting pan, and place them in the oven. Slowly, pour boiling water into roasting pan until it comes up about two third of the cheesecake. Bake for 1 hour.
After 1 hour, turn the oven off and open the oven door for 1 minute. Close the door and leave the cake in the oven for another 1 hour.
Remove the cheesecake from the roasting pan to cool in the refrigerator for at least 6 hours.
To serve, simply release the springform pan and remove the parchment paper. Place knife in a hot water before slicing and wipe clean after every cut.