Birch bark

I'm probably way off, but it almost looks like it's chocolate, and there is powdered sugar, or something like, on top. Then the slashes in chocolate, so they stay dark, the powder sort of gathers at the edges, and looks more light?

It's a cool effect. I would like to know how it was done, myself.

to me it looks like they used a medium darkness chocolate buttercream and smoothed it on roughly..if that makes sense...then chilled it, and went back over it with either a thinned down light colored buttercream so that the two colors blended or then brushed a light gray wash over the chilled chocolate buttercream and then scored the slashes so the dark showed through. just an idea.

I think your absolutly RIGHT!! I never thought about choc base so I tried a sample piece and molded the knot on to it although I painted hite over it with a wide paint brush dilutted with a little water. The brush bristles just enhanced a bark look although I did have to go back and paint in the slits with a choc brown and I used choc fondant but when I actuall do the cake I think I will make modeling choc so theslits with have that humped up appearence. You've been a huge help Thanks so much I will post a pic when I do the cake.

Cake Box

Megh...I actually like your practice cake.   I would just finish it up with airbrushing that grayish color.

Meg, not sure if your response was directed at me or not but  I didnt use butter cream I used choc fondant, to me I think that is what is used in the picture. Thats the exact picture my Bride wants also.

You could contact the creator of the original cake for advice:

http://www.thepeoplescake.com/gallery_non.php

I just tried a practice piece. I rolled out choc fondant and took a tooth pick to make the slits although they weren't raised up enough to suit me so I did add a strip of fondant that I rolled and put it around the slit and just worked it in with my fingers so it looked like one piece and I did th esame to make the knot I just rolled out a small ball and used a fondant tool for petals and pushed in the center then I just rubbed the edges into the piece of fondant and shaped it with my fingers til it looked like a tree knot. I dusted it with white petal dust but it wasnt bright enough so i tried white food coloring with a wide paint brush. The bristles gave it some texture also I did have to go back in the slits and paint with a choc brown but to me I thought it looked pretty close to your picture. Idk if the original creator did anything like that but thats just my take on it. I would wrap the fondant around the cake tier first then paint it so you didnt have to handle it after it was painted. I was happy with it so thats how I'm going to do the cake when I do it in June