Chocolate Yule Log (Bûche de Noël)

Lay a clean kitchen towel on the counter and sprinkle a thin layer of cocoa powder on it.The cocoa prevents sticking and adds extra chocolate flavor.
Turn the hot cake out of the oven onto the cloth.Flip quickly and confidently to keep the cake intact.
Carefully remove the parchment paper.Do this gently so the warm cake does not tear.
While the cake is still warm and pliable, roll it up in the cloth.Rolling while warm sets the shape and prevents cracks later.
Leave it to cool completely in this shape.The steam helps the cake mold naturally into a perfect spiral.

Beat the cream with powdered sugar and vanilla until thick, soft peaks form.The filling should be fluffy but stable enough to spread without running.
Refrigerate.Chilling keeps the cream firm until assembling.

Beat the butter until smooth.A creamy base ensures the frosting blends smoothly.
Add powdered sugar and cocoa.Start on low speed to keep the cocoa from dusting everywhere.
Add milk and vanilla to achieve a soft, spreadable consistency.The frosting should glide easily but still hold ridges for the bark effect.

Unroll the cake once it has cooled completely.The texture should be flexible without cracking.
Spread the prepared cream evenly over the top.Leave a small border at the edges to prevent cream from squeezing out.
Roll it up again without using parchment paper and place it on a serving plate with the seam side down.This keeps the roll secure and stable.
Cover the outside with chocolate buttercream.Apply a thin coat first, then build up texture.
Use a spatula or fork to create a bark pattern.Long strokes give a realistic wood grain effect.