Take the butter out of the fridge and put it aside.
Drain the yogurt by pouring it into a strainer lined with paper towel. Put it in the fridge for about an hour.
In the meanwhile, chop the dark chocolate into tiny bits. The smaller bits, the faster it melts.
Melt the chocolate in a water heated bowl. Be careful not to allow any water in the mixture as this will render the chocolate impossible to melt. Use a bowl almost as big as the pot.
Place the cake bottoms on pieces of wax paper. Spread the chocolate evenly on all the cake bottoms. I use a butter knife. It is almost like making a sandwich :)
Put the cake bottoms aside and let the chocolate harden.
Chop the Toblerone.
Melt it in a water heated bowl. I would not recommend using a microwave for this. Let it cool in the fridge for 10 minutes.
Whip half of the cream and mix in the Toblerone.
Put the raspberries, drained yogurt, sugar and vanilla seeds in a bowl. Whip it into a creme. You can also use a blender. Whip the rest of the cream and mix it into the raspberries.
Put a cake bottom in a springform tin, chocolate-side up. Spreading a thin layer of butter on the inside of the tin will prevent the cake from sticking to it.
Note: If your cake bottoms are different in size, you need to divide the fillings accordingly. If not, divide the fillings in half.
Add half of one filling and top with a cake bottom. It is not important which filling you begin with.
Repeat with the other filling.
Repeat with the other cake and let them sit in the fridge overnight.
Put the butter in a bowl and add vanilla extract. Stir until the butter turns into a creme. Add more vanilla to your liking. Let it sit in the fridge overnight.
Next day, take the cakes out of the springform tins and spread the softened butter creme on top and sides. It is easier if you place the cakes on the serving trays at this step.
It is time to make the fondant. Put 100 g. of marshmallows in a bowl and add 1 tablespoon of oil and 1 tablespoon of water. Cook it in a microwave for about 1 minute at the highest watts possible.
Warning: The marshmallows rise A LOT when cooked, so watch out! Turn off the microwave as soon as the marshmallows start rising. Also, they burn like napalm so be careful when handling.
Mix in 400 g. of icing sugar little by little while stirring. Once the fondant is dense enough to mould, dust the table with icing sugar, take the fondant out of the bowl and make a pizza-like pie.
Tip: You can put the fondant on a plate and cook it in the microwave for about 20 seconds if it gets too hard to stretch.
Carefully place the fondant on the cake. Cut off excess fondant. Fit the fondant using any flat item you have.
Use the excess fondant to make decorations. Your imagination is the limit.
Decorate the cake and make another batch of fondant for the other cake. We cut a hole in the bottom cake in order to fit it in the rack.
The final cake. Sorry for not getting a better picture.
Some pictures of the rehearsal cake.