Chocolate Christmas Log
- Sweet
- No rush
- French
- Oven
A rolled cocoa sponge spread with dark chocolate cream, rolled up and chilled, then finished with a cocoa dusting. A small, honest bûche de Noël made entirely in the oven.
- Total
- 2 h 51
- Prep 35 · Cook 16 · Rest 120
- Serves
- 6
- Difficulty
- Hard
You'll practice: Whisking · Folding
Instructions
-
Heat the oven to 200°C and line the 20 x 30 cm baking tray with parchment paper. While the oven heats, melt the butter in the small heatproof bowl set in the warm oven for 2 minutes, then take it out.
~2 min
-
Separate the eggs. Whisk the egg whites with the salt in a large bowl to soft peaks, then whisk in 60 g of the sugar a spoonful at a time until glossy and just firm.
~6 min
Adding sugar gradually stabilises the foam, and stopping at soft, glossy peaks keeps the whites flexible enough to fold without deflating.
Stop whisking the egg whites at soft, glossy peaks. Over-whisked whites turn dry and are hard to fold in without knocking out the air.
Whisking Whisk the whites to soft, glossy peaks that just hold a curl; over-whisking makes them dry and lumpy, so they tear instead of folding in.
-
Whisk the egg yolks with the remaining 50 g sugar in the second bowl until pale and thickened, about 3 minutes. Sift in the flour, 15 g of the cocoa powder and the baking powder, add the melted butter, and fold together. Fold in the egg whites in three additions until no streaks remain.
~3 min
Folding the whites in three additions traps air gently, and the melted butter must be folded in before them so it does not weigh down the foam.
Whisking Whisk the whites to soft, glossy peaks that just hold a curl; over-whisking makes them dry and lumpy, so they tear instead of folding in.
Folding Use a large spatula, cut down the middle and turn the bowl, folding gently in three additions until just combined; stop as soon as no streaks remain.
-
Spread the batter evenly in the lined tray and bake until the sponge springs back when pressed and a skewer comes out clean, 10 to 12 minutes.
~12 min
An even, thin layer bakes quickly and evenly, and the spring-back test shows the structure has set before it dries out.
-
While step 4 cooks
While the sponge bakes, chop the dark chocolate and put it in a bowl. Warm the cream in the oven in a heatproof bowl for 3 minutes, pour it over the chocolate, wait 1 minute, then stir to a smooth ganache. Chill it until thick enough to spread, about 20 minutes.
~20 min
Letting the hot cream sit on the chocolate melts it gently; stirring too early can split the ganache or make it grainy.
-
Turn the warm sponge onto a tea towel dusted with 5 g of the cocoa powder, peel off the parchment and roll it up inside the towel. Leave it rolled until cool, about 15 minutes.
~15 min
Rolling while warm trains the sponge to hold a curve, so it will not crack when rolled around the filling later.
Roll the sponge while it is still warm: cooling it flat makes it crack when you roll it later.
-
Unroll the sponge, spread over two thirds of the chocolate cream, leaving a 2 cm border, and roll it back up. Wrap in cling film and chill until firm, at least 2 hours.
~120 min
The border stops the cream squeezing out as you roll, and chilling sets the ganache so the log holds its shape when sliced.
-
Set the log on a wire rack, spread the remaining chocolate cream over the top, and dust with the last 10 g of cocoa powder before slicing.
~5 min
