Midnight Forest Bûche de Noël Shortbread

Pulse the cacao nibs, demerara sugar, and fleur de sel in a food processor until the texture resembles coarse, jagged sand. Set aside in a wide dish.

In the cleaned food processor, combine 340g flour, 120g powdered sugar, 20g cocoa, and 3.5g salt. Pulse briefly to aerate and unify.

Add 185g chilled cubed butter to the dry mix. Pulse until the fat is broken down into pea-sized crumbs that disappear into the flour.

Whisk the egg, 32ml sour cream, and 12ml vanilla paste. Stream into the processor while pulsing until a cohesive dough ball forms.

Divide the dough into three 23cm (9-inch) logs. Flatten each into a 28x8cm (11x3-inch) rectangle between plastic wrap and chill for 1 hour.

Melt 130g dark chocolate and 75g butter over a double boiler (simmering water should not touch the bowl) until glossy and smooth.

Whisk 30g powdered sugar, 18g flour, the egg yolk, and 6ml vanilla into the chocolate. Cool until it reaches a spreadable, paste-like consistency.

Roll one chilled dough rectangle on floured parchment to 38x15cm (15x6-inch). Spread one-third of the filling, leaving a 1.5cm (1/2-inch) border on one long edge.

Using the parchment as a guide, roll the dough tightly into a cylinder toward the bare edge. Repeat for all logs and chill for 25 minutes.

Preheat your oven to 175°C (350°F) and line a heavy baking sheet with fresh parchment paper.

Brush the chilled logs with a light egg white wash, then roll vigorously in the cacao nib mixture. Freeze for 15 minutes to set the 'bark'.

Slice the logs on a 45-degree bias into 2.5cm (1-inch) pieces. Arrange on the baking sheet with the spiral facing up.

Bake at 175°C (350°F) for 22 minutes until the shortbread is firm to the touch and the filling is set. Cool completely on the pan.