Cake
Step 1
Preheat oven to 375°. Coat an 18×13″ rimmed baking sheet or jelly roll pan with nonstick vegetable oil spray and line with parchment paper. Spray parchment. Place a big kitchen towel (it ought to be bigger than baking sheet) on a piece floor. Whisk equal elements powdered sugar and unsweetened cocoa powder in a small bowl to mix. Utilizing a fine-mesh sieve, mud towel with cocoa combination.
Step 2
Sift ¼ cup (31 g) all-purpose flour and ¼ cup (21 g) unsweetened cocoa powder by sieve right into a small bowl. Place 4 oz. bittersweet chocolate, coarsely chopped, 2 Tbsp. vegetable oil, and ½ tsp. vanilla extract in a small microwave-safe bowl and microwave in 15-second bursts, stirring between every, till melted. Let cool barely.
Step 3
Utilizing an electrical mixer on medium-high velocity, beat 6 massive egg whites, room temperature, and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt in a big bowl till foamy. With motor working, regularly add ⅓ cup (67 g) granulated sugar and beat till stiff peaks type and meringue is shiny.
Step 4
Utilizing clear beaters, beat 3 massive egg yolks, room temperature, and ⅓ cup (67 g) granulated sugar in one other massive bowl till pale and thick, about 4 minutes. Beat melted chocolate combination into yolk combination till no streaks stay.
Step 5
Use a big rubber spatula to fold in meringue, leaving some streaks. Fold in dry components simply to mix (do to not overmix).
Step 6
Scrape batter onto ready pan; clean into an excellent layer. Bake till prime of cake is dry and comes again when gently pressed and edges are beginning to draw back from sides of baking sheet, 10−12 minutes; let cool barely.
Step 7
Run a knife alongside edges of baking sheet to loosen, then invert cake onto ready towel. Rigorously peel away parchment. Beginning at one of many lengthy sides, gently roll up heat cake right into a log inside towel. Switch, seam facet down, to a wire rack and let sit till cake is simply barely heat, about 20 minutes.
Step 8
Mix remaining 2 Tbsp. granulated sugar and a couple of Tbsp. scorching water in a jar, seal, and shake vigorously till sugar is dissolved, about 1 minute. Uncover and stir in 2 Tbsp. cognac, darkish rum, or brandy. Unroll cake and brush prime with cognac syrup.
Do forward: Cake might be made 1 day forward; switch to baking sheet, cowl with plastic wrap, and retailer at room temperature.
Chestnut Mousse
Step 9
Place 1 Tbsp. chilly water in a small bowl and sprinkle ¾ tsp. unflavored powdered gelatin over; put aside.
Step 10
In the meantime, carry 6 oz. vacuum-packed or jarred roasted chestnuts, 1 cup entire milk, ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt, and ½ tsp. vanilla extract to a simmer in a small saucepan and cook dinner till chestnuts are falling aside and milk is decreased by half, 12−18 minutes. Add gelatin combination, stirring to dissolve.
Step 11
Switch chestnut combination to a meals processor and course of till very clean. Let chestnut cream cool.
Step 12
Whisk 1 cup heavy cream in a medium bowl till delicate peaks type.
Step 13
Utilizing electrical mixer on medium-high velocity, beat 2 massive egg yolks and ¼ cup (50 g) granulated sugar in one other medium bowl till pale and thick, about 4 minutes. Beat in chestnut cream. Utilizing a rubber spatula, gently fold in whipped cream simply till integrated.
Step 14
Unfold chestnut mousse over prime of cake, leaving a 1″ border. Roll up cake and place, seam facet down, and return to baking sheet. Chill till mousse is ready, at the very least 3 hours.
Meringue Mushrooms
Step 15
Preheat oven to 200°. Utilizing electrical mixer on medium-high velocity, beat 2 massive egg whites, room temperature, and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt in a clear medium bowl till foamy. With motor working, regularly add ⅓ cup granulated sugar and beat till stiff, shiny peaks type. Add ⅓ cup powdered sugar and 1 tsp. distilled white vinegar and beat till meringue may be very dense (peaks ought to nonetheless be stiff and shiny). Switch meringue to piping bag fitted with medium spherical tip.
Step 16
Pipe 1″-long cones (these would be the mushroom stems) and quarter-size rounds (the mushroom caps) onto a parchment-lined baking sheet. Utilizing a fine-mesh sieve, mud mushroom caps with unsweetened cocoa powder. Bake, rotating as soon as, till meringues are dry, 1½−2 hours.
Step 17
Utilizing a small paring knife, make a small gap in middle of flat facet of mushroom caps. Working one after the other, unfold a dab of chocolate (from 2 oz. bittersweet or semisweet chocolate, melted, cooled barely) on flat facet of mushroom caps with an offset spatula and match smaller finish of mushroom stems into gap, urgent to stick. Let sit till chocolate hardens.
Do Forward: Meringue mushrooms might be made 3 days forward. Retailer hermetic at room temperature.
Chocolate Buttercream and Meeting
Step 18
Utilizing electrical mixer on medium-high velocity, beat 2 massive egg yolks, 1 massive egg, and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt till pale and thick, about 4 minutes.
Step 19
In the meantime, match a small saucepan with sweet thermometer and convey ½ cup (100 g) granulated sugar and ¼ cup water to a boil over medium-high warmth, stirring with a heatproof rubber spatula to dissolve sugar. Proceed to cook dinner, swirling often (however not stirring), till thermometer registers 248° (that is the firm-ball stage).
Step 20
With the motor working, regularly pour sugar syrup round edges of egg combination the place eggs meet sides of bowl (you need to keep away from the beaters to stop syrup from splattering). Beat till combination is mild and fluffy and out of doors of bowl is cool to the contact, about 5 minutes.
Step 21
Regularly beat in 1 cup (2 sticks) unsalted butter, room temperature, reduce into items, a chunk at a time, mixing till integrated earlier than including the subsequent piece. If combination appears to be like soupy or curdled, proceed to beat till an emulsion varieties and combination is mild and thick (this might take a number of minutes). Beat in 5 oz. bittersweet or semisweet chocolate, melted, cooled, and 1 tsp. vanilla extract.
Step 22
Utilizing a protracted serrated knife, trim ½” from every finish of cake to create clear edges; discard (or eat!). Working from one finish and chopping at a forty five° angle, slice off a 2″ piece of cake. Lower one other 2″ piece from similar finish, this time chopping perpendicular to cake roll to create a squared off finish.
Step 23
Dab 1 Tbsp. buttercream on angled sides of every 2″ piece of cake. Place each bit in opposition to roll to create branches, positioning one on prime and the opposite on the facet.
Step 24
Utilizing an offset spatula or butter knife, unfold buttercream over outdoors of roll, leaving reduce ends uncovered to disclose spiral. Use spatula to create textured strains in buttercream to appear like tree bark.
Step 25
Simply earlier than serving, mud cake with powdered sugar and adorn with meringue mushrooms.
Do forward: Chocolate buttercream might be made 2 days forward; cowl and chill, or freeze as much as 1 month. Deliver to room temperature and beat once more earlier than utilizing. (Thaw frozen buttercream in fridge in a single day earlier than bringing to room temperature.) Bûche de Noël (with out powdered sugar and mushrooms) might be made 1 day forward; cowl and chill.
Editor’s observe: This bûche de Noël recipe was first printed in December 2014. Head this manner for extra of our greatest Christmas desserts →
