Pour the heavy cream into the jam jar. Add the confectioners’ sugar and a pinch of salt. Now shake! Shake continually for 3-5 minutes until you start to feel the liquid inside of the jar start to stiffen up. If your arms get tired, pass it off to a friend or place it in the freezer for a minute to take a break.
Once thickened, use it to top any dessert or your favorite coffee drink!