Preheat water bath or precision oven to 176°.
Combine water and granulated sugar in a medium-large saucepan over medium heat. Stir until sugar dissolves and then allow to boil until it begins to turn a golden brown, caramel color.
Turn off the heat and stir in the brown sugar and heavy cream until all of the brown sugar has dissolved and the mixture is homogenous. If it seizes and clumps, return to heat and continue to cook, stirring constantly until everything melts together.
Stir in the vanilla and a pinch of salt.
Allow mixture to cool for 10-15 minutes or until lukewarm.
Whisk in the egg yolks until fully combined.
Add mixture to jars of your choice and seal fingertip tight for mason jars or normally for Weck jars.
Cook for 1.5 hour at 179° and then refrigerate until cooled and set.
Serve with unsweetened freshly made whipped cream.