Ok, I've decided to post my progress pictures and descriptive steps to how to make a birch bark tree cake. When I was looking around for how to do it when this wedding cake came up I never really got a good answer and muddled through the process. I wanted to help anyone else out who wants to attempt it but, like me, didn't know where to start! I do want to let you all know that "The People's Cake" has a tutorial on this as well. They make absolutely stunning cakes so I would always recommend checking them out :) I'm sure how they do it is completely different but when I made it, their tutorial wasn't out, so this is what I came up with.
Here is my finished product, just to give you an idea of our end goal :)
Ok so here we go! The first steps is to bake and frost your cakes. I don't use a crusting buttercream so I had to put mine in the fridge to really firm them up before working with them and stacking them. Before I stacked them I rolled out a circle of light tan fondant and lay it on top of each tier. I then went around with scissors and trimmed up any access fondant from the edges. It doesn't have to be perfect but you will want it as smooth and as close as you can get it!
Once the fondant is on each tier, stack them as you usually would :)
Here is a close up of the fondant circles that were trimmed. The fondant I'm holding is what I planned to use for the sides of the cake. It's a brownish, gray but you could even go a little lighter than this (or more brown depending on the effect you are going for.)
Once I decided the color I rolled out a strip on fondant wide enough (bigger than 4 inches) and longer than the circumference of the tier I was working on (taking you back to geometry with 2*pi*r). If your favorite subject wasn't Geometry, like mine was, use a soft tape measure to see how far around your cake is. It's ok to have more than enough! Once it was rolled out I used a ruler and trimmed it to the height of the cake. I used a really sharp knife in order to get a nice clean cut of fondant. Once it was trimmed, I then began rolling out "snakes" of the same color fondant. I placed the "snakes" where I wanted them on the cake and then lighter pressed them into the large piece of fondant. It might be helpful to use a bit of alcohol to attach the "snakes". I then took my pointed fondant tool and went around the edges of the "snake" blending it into the larger piece. Once all the way around the snake I used the pointed tool again to press a slash into the center of the "snake". Be sure to vary it a bit and do smaller slashes and deeper slashes. You need to work a bit quickly to ensure that your long piece of fondant doesn't dry out, you are going to need it to be flexible still! At this time you can also add knots to your cake.
After you finish your length of fondant with slashes, bring it to the cake and starting in the back of the cake, start wrapping your piece of fondant around the entire tier. You will end in back again, gently trim and blend the seam that is there. After painting it, the seam will be blended even more.
Continue with the other tiers and do the same technique all the way down. For the carved heart, just form the "snakes" into that shape and do the same steps as above. Be sure to place the heart in the center of the fondant strip so that it will show up on the front of your cake!
These next two steps you may be able to flip flop. It could be easier that way, but obviously I haven't tried it! To get the dark slashes I used a thinned out brown food coloring and carefully painted inside each slash.
I then took white food coloring and used a wide (2ish inches) brush and painted around the entire cake. Don't use too much at first, you can always go back and add more but good luck taking it away! Once the white is done, use an even thinner brown food color and paint around the edge of the slashes. Below you can see the painted tier and the unpainted tier underneath it.
Do each tier!
Once it was all done, I decided it needed a little bit of something, so I again used the brown food color to trace the edge of the cake just to make them "pop" and have definition.
I hope I didn't miss anything! Feel free to ask me any questions you might have!
Happy Cake Making!!