In a large pan combine the heavy cream and one cup of sugar and bring to a simmer over medium heat.
In a large bowl, whisk the egg yolks and the remaining 1/4 cup of sugar.
Whisking constantly drizzle a small amount of cream mixture into the yolks, slowly, and to keep the eggs from curdling, do this a few more times before pouring the yolk mixture back into the cream, whisking constantly.
Cook over low heat until the mixture is thick enough to coat the back of a spoon.
Strain the mixture and whisk in the buttermilk, vanilla essence and salt.