Heat the cream and milk in a small pot over low heat until very warm but *not* hot. Remove from heat and immediately stir in the blossoms. Allow to cool to room temperature, then strain through a mesh strainer placed over a bowl, pressing gently on the blossoms to get all the liquid out. Discard the blossoms, reserving the lilac-infused cream mixture.
Heat the lilac-infused cream mixture and the honey in a small saucepan over low heat until hot but *not* boiling. Remove pan from heat and stir in the gelatin and vanilla extract and stir until the gelatin dissolves completely.
Evenly divide between 6 8-ounce mason jars or 12 4-ounce mason jars and allow to cool to room temperature before covering with a lid and placing in the refrigerator. Refrigerate for at least 4 hours or overnight. Serve chilled. Will keep in the refrigerator for up to 5 days.