Bakeawish... love it! Is it buttercream? How did you do it? Thanks.
These are the supplies you need for the technique I came up ith,
2 inch chip brush..these are the el cheapo kind with kinda stiff bristles
some white powdered food coloring I got mine at a local baking supply store
teeny bit of black food coloring
ivory food coloring
cover cake in black fondant
make your branchy nubs and blend in with gumpaste tool damp paint brush etc.
I kind of marbled my tan and light brown fondant together then started with a small ball and "snaked" alternating colors in a pinwheel pattern then roll out to get a tree ring effect for the tops of the tiers.
then I made a snake of black fondant and rolled it thin and wrapped it around the upper edge of the cake and blend it in to give it that little "lip: that sticks up and hides the edge of your tree rings.
I had two small containers of thinned royal icing one colored l ivory and one light grey with the powdered white coloring to make it opaque i did an undercoat of the ivory brushed on basically just hold the brush against your cake and spin your turn table so the grooves go horizontally I did a very thin coat just to give it a warm undertone. Once that sets up a bit it set, I coated it with the light grey..then I dry brushed it a bit with the powderd white color then carve it and and the bark nicks with a bamboo skewer. I saw somehwere that the original was done with a chocolate wrap..but that option was not available for me to use at my bakery..Hope this helps you I would definitley play with the technique ona small cake dummy first to get the results you want .:o)