Separate the eggs and add the egg whites to a large bowl, whisk until soft peaks form.
Add the sugar and whisk again until combined.
Add in the vanilla extract, flour and cocoa powder, and fold through until combined.
Pour into prepared tin and bake for 6-8 minutes.
Place a large piece of parchment onto a work surface and sprinkle with some golden caster sugar. Tip the sponge out and peel off the baked piece of parchment, then while the sponge is still hot, roll up the excess paper and begin to roll the sponge horizontally, with the paper still in it. (This helps to shape the sponge). Place to one side to cool.
Meanwhile whisk the cream then add the cinnamon and honey and fold through.
Once the sponge is cool, carefully unroll, then spoon the cream over the entire sponge.
Carefully roll the sponge back up and place on a serving board, cut off 1/4 of log at and angle and fix to make a branch. Then place the log in the fridge.
Meanwhile make the butter cream, melt the dark chocolate in the microwave, add the peanut butter and mix until smooth.
Place the buttercream in the fridge to thicken a little for 5 minutes.
Spoon the buttercream all over the yule log and dust with icing sugar.