Beat the yoghurt until nice and smooth. Do the same with the cream too.
Mix them and add the powdered sugar and vanilla. Soak 2 packs of gelatin in 1 cup of water and then dissolve it in the microwave for a few seconds and add it to the mixture.
Pour a little bit of the mixture into a rectangular cake mold, then add a layer of biscuits, then a little of the mixture, a little of the biscuits again the remaining mixture. Put the jellied yoghurt in the freezer for 30 minutes.
Use the third gelatin packet for the strawberry jam, add it on the very top and then return the cake to the freezer for about 20 minutes.
Invert it and leave it in the refrigerator.