Whisk the sugar, cornstarch and salt in a medium bowl. Slowly pour in 1/4 cup of the heavy cream while whisking continuously. Slowly whisk in the remaining 1/4 cup.

Slowly pour the milk into the bowl, whisking continuously. Pour the mixture into a saucepan and clean and wipe the bowl.

Heat the mixture over medium heat, stirring constantly with a wooden spoon and scraping along the sides and bottom. When the mixture comes to a simmer, reduce the heat to low and continue stirring for 1 minutes. Remove from the heat and stir in the vanilla, butter and vanilla bean seeds.

Pour the mixture back into your now-clean bowl, place plastic wrap directly onto the surface and refrigerate for a minimum of 4 hours before serving.