Pre heat the oven at 160° C / 320 F
in a bowl mix starch, flour, sugar, baking powder (guar gum if you want to) and mix well
add vanilla extract, oil and milk and whisk well until you have a smooth, clump-free batter that is not too liquid and that can be spread with a spatula
cover a baking sheet with parchment paper (I used a 35*25 cm one) and spread the batter on it until you have a rectangle that is less than half inch thick
bake for 12-15 minutes max, the cake needs to be golden and soft (or it will crack when rolling)
once it's out of the oven, wait a couple minutes then very carefully remove it from the parchmament paper and place the cake on top of it again
place a napkin on top of the cake and carefully roll them together along the longer side
let the cake roll rest for at least 10 minutes
in the meanwhile prepare your favorite filling, I've used a simple vegan chocolate spread, but you can go for whipped cream, custards or simply jam
you will also need a liquid mixture to moisten the cake before filling it: you can either mix some water with sugar, or water and rum or some orange juice aswell
now unroll the cake, remove the napkin and lightly wet the cake with the liquid mixture
evenly spread the filling of choice in a thin layer all over the cake
with the help of the parchment paper roll the cake up again and close it at the two ends
refrigerate for 15-20 minutes
once out of the fridge, cut half an inch out of the two endings (so you'll have a clean cut of the roll) and cut 2 small slices to place at the sides of the longer cake
I covered the yule log with melted vegan dark chocolate, let it rest for a few minutes so that it solidifies a bit then created the "bark" lines with a fork
for the decoration you can add sliced almonds, fresh berries, pomegranate seeds and dust it with powdered sugar