Do you really have enough frosting left for a cake? Even if it's a sheet cake, it takes a lot. I use cocoa powder for frosting, but I don't know that that's meaningful. For myself, I'd make a full batch of the chocolate frosting for the cake, and save the leftover vanilla buttercream to decorate it with. Adding a little color if called for would work fine. :)

It's actually for the Buche de Noel so I'm not sure how much buttercream it will take. I was thinking about 1/4" or so then covered with ganache. Would that be thick enough layer? I will go ahead and make a whole separate batch of chocolate just to be sure. Using cocoa powder :-) thanks!

Putting a layer of buttercream on and then getting ganache over the top of the buttercream is going to be tricky IMO. You may regret trying.

Oh phooey I wanted 2-tone. Oh well I'll just use buttercream then and use a veg peeler and a block of dark chocolate for a little contrast. Thanks for the heads-up!!

Good idea, Ganache is hard to control. Shaved chocolate looks barky.

You're right about the log. That would take a lot less frosting. But then if you want to make ridges and stuff... You might have enough.

You could also use the leftover frosting for a crumb coat in one color, and do the textured and sculpted frosting in your second color.

I do believe that one should not waste, but in cooking, that can be the enemy. Assuming one isn't on an impossibly tight food budget (I don't think most who post here are), it's important to remember that we're not pioneers, and eggs, butter, oil and sugar are no longer desperately dear. It's worth it to make enough frosting, or use enough fry oil, or be willing to break an extra egg. It makes life much easier, and you can use the extra eggwhite making spiced nuts. Similarly, you can use extra frosting to make leaves, bugs, fungi, etc.

Just saying.

I like that idea... As far as my granddaughter is concerned, the more frosting the better anyway! Thanks for all your patience and input!

Thank you all very very much for "holding my hand" during this learning experience. Hope everyone has a wonderful day today, Happy Hannukah and joyous Christmas Eve.

Oh, that's pretty, and I'm sure it's as delicious as it looks.

I'm too late for the "two toned frosting" piece, but I found this while looking for a gluten free chocolate roulade, it has a layer of frosting topped with ganache. Doesn't mean it's easy or works well, of course, but it looks pretty good here:

https://www.freefromheaven.com/recipes/chocolate-roulade/

Happy Everything!

Annie

Well, I brought home zero leftovers. There was almost a fight over the last couple of inches! It did come out much better than I had thought it would. But my goodness what a mess it made. I still have to go clean the kitchen. Ugh. At some point well before next season's baking frenzy gets underway I am going to make one and fill it and put it in the freezer just to see what that does to the taste/texture.

Annie, that recipe looks almost exactly like the one I used except for mine has a smidge of cake flour. The filling looks like it would be very rich and creamy.

Edie, that's a success all around! Congratulations!

It looks beautiful, and what's more, it looks appetizing. No wonder that they were fighting for it. :)