1 layer for a 10″ round cake:
7 oz (200 grams) raspberries fresh or frozen
1/2 cup (70 grams) powdered sugar
Seeds from 1 vanilla bean
5 sheets of gelantine or 5 tsp of gelantine powder
(use the directions described on the package)
2 1/8 cup (500 ml) heavy cream
1 large disposable piping bag
Leave the gelantine sheets to soften in a bowl with ice cold water for 30-45 minutes.
Place the raspberries in a small casserole along with the powdered sugar and vanilla seeds. Slowly heat up the raspberry mixture, just until it starts to boil. Stir with a whisk and let the berry mixture shimmer for 8-10 minutes. It is a good thing to check the temperature before taking it off the heat. When it is 160-170 F (75 C) in temperature take it off the heat and let it cool down for 5-10 minutes before you continue.
Note: You can add more powdered sugar if you want it to be sweeter.
Whip the heavy cream until it reaches soft peaks.
Make sure that you have the berry mixture, gelantine and whipped cream all in front of you before you continue. Next take up the gelantine sheets and squeeze them for water. Put them or the gelantine powder mix into the berry mixture which should still be warm to the touch and stir with the whisk until it is all melted. Next add 1 cup of the whipped cream to the berry mixture and give it a good stir.
The mixture should now be luke warm. Then pour the berry and cream mix back into the bowl with the whipping cream and carefully fold it in until it is thoroughly combined.
Fill the raspberry mousse into a disposable piping bag and fill your cake.
Place the cake in the refrigerator overnight.
Tip! If you like you can add some chopped dark chocolate when the raspberry mousse is combined with the whipped cream.
Working with gelantine can be tricky, so if you have never tried it before then make only the mousse and use it for a delicious dessert with some fresh berries. This will help you troubleshooting any problems you may run into and you wont end up with a spoiled mousse that should have been used in a cake.
It is also important that the berry mixture is warm but not hot before the gelantine sheets is added. It will not give you any problems melting the gelantine, but a too hot berry/cream mixture, will give you a very liquid mousse that is not pipeable for cake filling.
Cakes filled with raspberry mousse must be kept in the refrigerator. Take the cake out 1 hour before serving.