Whisk the fromage blanc and sugar together in a bowl until the sugar dissolves. Add the vanilla seeds and whisk to incorporate. Heat the milk in a very small saucepan over low heat to 50°C (120°F).
Soak the gelatine in iced water until hydrated and then squeeze out the excess water. Add the gelatine to the warm milk, and stir to dissolve. Leave for 1 minute to cool slightly.