In a small dish, mix together gelatin and cold water. Set aside for about 5 minutes.
In a medium saucepan, add heavy cream, vanilla, maple syrup, lemon zest, and salt. Heat the mixture until warm, but not hot or boiling. Stir in gelatin until completely dissolved, then remove from heat and let cool for 5 minutes. Add creme fraiche to a large mixing bowl, then slowly whisk in cream mixture until smooth. Divide mixture evenly between six jars. Chill for at least 4 hours.
While the panna cotta chill, in a large bowl, mix together the strawberries, rosemary, and sugar. Let sit at room temperature for at least 30 minutes, or until the juices are released.
When ready to serve panna cotta, add one tablespoon of the mango syrup to each jar, then scoop a heaping spoonful of macerated strawberries on top of each panna cotta jar. Enjoy.