This framboisier cake is like a fraisier made with raspberries: layers of sponge cake filled with mousseline cream and raspberries. You can top it with powdered sugar or a layer of marzipan.
In a small saucepan, combine the sugar and water on medium-high heat. Bring it just to a simmer, and leave it to simmer, swirling often, until all the sugar is dissolved. Remove from the heat to cool completely.
When the syrup has cooled, add the Chambord (more or less than suggested above, depending on how flavourful you want the syrup), and stir. Set aside for later.
To make the white chocolate buttercream
Combine the swiss meringue buttercream with the melted chocolate. You can do this in your mixer with the paddle attachment, or with a spatula by hand. Personally, I like to do this with the mixer. It’s easier. Make sure the two components are roughly the same temperature so that the emulsion doesn't break.
To assemble the framboisier
Place 1 cake round on your cake turntable, cut-side up.
Brush on a half of soaking syrup
Meanwhile, brush the cut-side of the other cake round with the rest of syrup and set aside.
Top the cake round on the turntable with a scant ⅔ cup buttercream, and spread it to cover the surface of the cake.
Place the raspberries over top.
Top with another scant ⅔ cup buttercream, and spread it carefully over the raspberries, without pressing too much.
Place the second cake round, cut-side down, over the buttercream layer. Press it down very gently.
If you are topping your cake with a marzipan layer, roll it out to fit the top of the cake. You'll need to spread a thin layer of buttercream over the top of the cake to glue the marzipan down. If not using marzipan, dust generously with powdered sugar just before celebrating.
Notes
To make a fraisier cake, use the same recipe but replace the raspberries with strawberries.