Lightly grease the ramekins: Spray the ramekins with cooking spray or melted butter, then use a paper towel to wipe out most of the oil, leaving only a light residue. This will help the panna cotta release if that’s how you choose to serve the dessert. If you’ll serve the dessert in the jars, then you don’t need to grease the jars.
Bloom the gelatin: Pour the half and half into the saucepan and sprinkle the powdered gelatin evenly over top. Let soften for 5 minutes or until the surface of the milk is wrinkled and the gelatin grains look wet and slightly dissolved.
Dissolve the gelatin over low heat: Set the saucepan over low heat and warm the milk gently, stirring or whisking frequently. The milk should never boil or simmer. If the mixture starts to steam, remove the pot from the stove and let it cool down. Milk should be hot, but not boiling. Gelatin melts at body temperature, so you don't need the half and half to boil to melt the gelatin.
Check to make sure the gelatin is dissolved: The mixture should be smooth. Either touch the mixture and rub half and half between your fingers to see if it’s gritty, or dip a spoon in the half and half to see if you can detect grains/grit in the half and half.
Dissolve the sugar: Stir the sugar into the half and half and continue warming until it dissolves. It should take about 3-5 minutes to dissolve the sugar. Remember not to boil the mixture, as it will break down the “gelling” ability of the gelatin.
Whisk in Vanilla and the Salt: Remove the saucepan from the heat. Whisk in the vanilla bean paste and the salt.
Pour half and half mixture into the ramekins or jars and chill: Divide the mixture evenly between the prepared ramekins or jars and put in the refrigerator to chill.
It will take about 4 hours to set if you will invert the panna cotta. If you’ll serve from the jars, you only need to set the mixture for about 2 hours. They can be chilled over night.
To serve “plated”, here’s what you to Fill a large bowl with warm water. Wipe a dessert plate with a damp paper towel. To release the panna cotta edge from the cup, run a thin knife carefully around the sides of a ramekin. Dip the ramekin in the warm water up to its rim, and hold it there for about 5 seconds.
Invert the ramekin over the plate and shake gently to help the panna cotta fall out. It should fall out on the plate easily. (If it does not, return to the warm water bath in increments of 2 seconds.) Reposition on the plate if desired—because you wet the plate, it should be easy. Serve immediately,
Or, serve in a clear jar! You can serve the panna cotta in jar for a rustic treat, topped with macerated strawberries.