Steep pretzels in cream for 1 hour, then strain and push all cream out of pretzels; discard pretzel mash and keep cream. Reduce the beer to 1/2 cup. Let beer come to room temperature. Sprinkle gelatin over beer and let sit for 5 minutes. Stir over medium heat just until the gelatin dissolves, but does not boil, about two minutes. Add the cream, sugar and salt. Stir over low heat till the sugar dissolves, about three more minutes. Remove from heat and let cool slightly. Pour the mixture into two martini glasses, dividing equally. Cover and refrigerate at least 6 hours, best overnight.