Start with the gelatine. Fill a medium-sized bowl with cold water. Add the gelatine. Soak for 5 minutes or until it softens.
Put the jam into the bottoms of 4 glasses. Put the glasses in your fridge.
Get a small (16–18cm) saucepan. Add the cream, caster sugar, vanilla seeds and vanilla pod. Whisk everything together. Warm the mixture to just under simmering point. Do not let it boil. Take the pan off the heat.
Squeeze the gelatine dry. Add it to the cream mixture and stir until it is completely dissolved. Leave to cool for 5 minutes. Take out the vanilla pod.
Put the crème fraîche into a large measuring jug. Gently whisk in the warm cream a little at a time until the mixture is smooth. Leave to cool for 10 minutes.
Take the 4 glasses out of your fridge. Carefully pour the cream against the inside of the glasses (this stops the cream and jam from combining, meaning that you can get clear layers) over the top of the jam. Leave to set for 3 hours in the fridge.
To make the basil sugar, put the basil and granulated sugar into a small mortar and pestle. Grind together until you have a coarse green powder.
Put the raspberries on top of the panna cottas. Sprinkle the basil sugar over the top.