Classic Bûche de Noël with Chocolate Ganache and Marzipan Mushrooms

Instructions

1. 1

   Preheat oven to 350°F and line a 15x10-inch jelly roll pan with parchment paper. Beat egg yolks with 1/2 cup sugar until pale and thick. In a separate bowl, whisk together cocoa powder, flour, and salt. In another clean bowl, whip egg whites until soft peaks form, then gradually add remaining 1/4 cup sugar until stiff peaks form. Fold the cocoa mixture into the yolk mixture, then gently fold in the egg whites in thirds.

2. 2

   Spread batter evenly in the prepared pan and bake for 12-15 minutes until the cake springs back when lightly touched. Immediately turn the cake onto a clean kitchen towel dusted with powdered sugar. Peel off parchment paper and roll the cake up in the towel starting from the short end. Cool completely on a wire rack.
3. 3

   Whip 2 cups heavy cream with powdered sugar and vanilla extract until soft peaks form. Be careful not to overwhip. Chill until ready to use.

4. 4

   Place chopped chocolate in a heatproof bowl. Heat 1 cup heavy cream in a saucepan until it just begins to simmer. Pour hot cream over chocolate and let sit for 2 minutes, then stir from center outward until smooth and glossy. Stir in butter until incorporated. Let cool to spreadable consistency, about 30 minutes.

5. 5

   Carefully unroll the cooled cake and remove the towel. Spread the whipped cream filling evenly over the surface, leaving a 1-inch border. Gently re-roll the cake without the towel, seam side down. Transfer to a serving platter.

6. 6

   Cover the entire log with chocolate ganache using an offset spatula. Create bark-like texture by running a fork lengthwise along the surface. Chill for 30 minutes to set.

7. 7

   Roll small pieces of marzipan into mushroom cap and stem shapes. Dust caps lightly with cocoa powder for a realistic look. Insert stems into caps and arrange around the base of the log. Dust the entire cake lightly with powdered sugar to resemble snow.