1: Prepare a clear juice with 500 g raspberries and 50 g caster sugar, following the exact method for clear strawberry juice. This can be done several days ahead.
2: Put 1 sheet gelatin in a small bowl of cold water to soften.
3: Pour 125 g of the raspberry juice into a small saucepan on medium heat and heat gently to a maximum of 140°F (60°C). Add the softened gelatin after draining, mix well and leave to cool.
4: Divide the jelly between the tart cases, then put on a wire rack and refrigerate for about 2 hours until the jelly sets.
5: Pour the rest of the raspberry juice into a bowl, add 30 g caster sugar and 200 ml liquid cream, then mix thoroughly with a whisk.
6: Transfer the mixture to a siphon, seal it, and pierce a gas cartridge.
7: Once the jelly in the tarts has set, pipe a pretty rosette of raspberry cream...
8: ...on top of each tartlet.
9: Your double raspberry tartlets are ready. You can add a finishing touch with a sprig of mint or verbena.
Remarks
This recipe can easily be made with strawberries instead.