Either chocolate ganache (heat cream until almot boiling, add broken up chocolate stir until melted then allow to cool. refridgerate for several hours then bring to room temp and whip until it retains a peak.)
Swiss buttercream - much lighter and less sweet than traditional buttercream - and then flavour it as you like. If interested I will post a proper recipe, but basically it is egg whites with granulated sugar, butter and flavouring.
I prefer dark chocolate at least 70% cocoa solids (you can add sugar to it but I think it is better without, balancing the sweetness of the cake. I use roughlt on carton of double cream to one bar of chocolate I think it is something like 268ml to 6oz choc)
Swiss meringue buttercream
Ingredients 4 large egg whites 220 g granulated sugar 1 lbs unsalted butter, room temperature 1 Tbsp lemon extract, almond extract, orange extract, or pure vanilla extract or up to 30 ml light rum, framboise, pear William, or kirsch
1. Lightly whisk egg whites and sugar together over simmering water until egg-white mixture is hot to touch. 2. Pour hot whites into a room-temperature bowl and whip with a wire whip until double in volume. When the mixer stops, the meringue should not move around in the bowl. Meanwhile cut up butter into 2-inch pieces. (The butter should be slightly moist on the outside but cold inside.)
3. On your mixer, remove the whip and attach the paddle. Add half the butter into the bowl immediately and pulsate the mixer several times until the meringue has covered the butter completely. Add the balance of the butter and pulsate mixer several times. Slowly increase the mixer's speed, starting with the lowest speed and increase the speed every 10 seconds until you reach a MEDIUM-HIGH speed.
4. Continue beating until the mixture begins to look light and fluffy. Stop the mixer and scrape the bowl. Reduce speed to LOW. Add flavoring and continue to beat on LOW speed for until mixed.
5. Leftover buttercream can be placed in plastic containers with lids and kept in the freezer for up to 3 months. Defrost completely (several hours) and rewhip before using.
I do a meringue frosting, basically whip up egg whites until they are stiff, melt sugar until it is runny but hasn't changed colour yet, and then add the melted sugar to the whipped egg whites in a steady stream while beating the whole time (I use an electric beater). You should end up with a lovely light soft gooey icing, a bit like marshmallow or the soft gooey bit inside meringues. I add vanilla seeds once it's done too.
It is much lighter than a butter or cream based icing.
I guess it is ismilar to Comeoveneer's recipe but without the addition of the egg.
The hot sugar cooks the egg whites so no need to worry about raw egg whites.