run a cup full of hot water, the swiss rolls cut nicely with a hot knife

soak a paring knife in the hot water

open the swiss rolls, with the hot knife cut one on the diagonal to make three little branches for your log

if the chocolate breaks a little that's ok because you're going to add a tiny bit for bark in the next couple steps

dab a little frosting on the cut end and stick it to one of the branches, repeat with all three branches

spread a small amount of frosting on the top of the swiss rolls and their little branch as well

use a fork to draw lines for bark, this is quick and easy, don't make it perfect, trees are seldom perfect

set your logs on a baking sheet or plates if you're ready to serve them up

cut mini-marshmallows into 1/3 and 2/3rd pieces

roll the smaller piece into the stem and stick it to the cut end of the larger piece

repeat making as many mini-marshmallows as you'd like, prefer 2-3 per yule log

once they're done use a clean paintbrush to flick cocoa powder over the mushrooms

affix to the logs with a small amount of chocolate frosting

if you're planning to serve them later simply lightly cover with plastic wrap or foil

if you add greens to the plate be sure to let your guests know it's not edible