Yule Log or Buche de Noel - Gluten Free

Yule, Winter Solstice, or however else you'd like to refer to it, arrives on December 21.  You still have a day to consider making this very traditional yule log cake! I have made a version very similar to this one before, using Nick Malgieri's recipe start to finish (except the marzipan). I still prefer his cake but it has flour, and this year I was going to a party where two people eat gluten-free.  Most of us have friends and family where this is an issue, so I dug through recipes online to find a combination that would work for even our gluten-free friends.  If you're just now thinking about it, the mushrooms are easy to make a day or so in advance. The rest of it is best if it is made the day of, because I prefer this silky buttercream never chilled in the fridge.

Cake: Nigella's Yule Log (naturally gluten free as it does not contain flour, only cocoa powder!)
Icing: Nick Malgieri's Coffee Buttercream (the silkiest around!)
Mushrooms: Meringue Mushrooms from Joy of Baking (simple but impressive)

Since recipes can't be copyright protected, and I am always worried something I have used will get taken down, I will copy them all here, but with complete respect and credit to their originators.

Cake from Nigella's Yule Log Recipe
  
6 large eggs (separated) 
¾ cup superfine sugar 
½ cup unsweetened cocoa 
1 teaspoon vanilla extract

1. Preheat the oven to 180°C/gas mark 4/350ºF.
2. In a large, clean bowl whisk the egg whites until thick and peaking, then, still whisking, sprinkle in 50g / ¼ cup of the superfine sugar and continue whisking until the whites are holding their peaks but not dry.
3. In another bowl, whisk the egg yolks and the remaining superfine sugar until the mixture is moussy, pale and thick. Add the vanilla extract, sieve the unsweetened cocoa over, then fold both in.
4. Lighten the yolk mixture with a couple of dollops of the egg whites, folding them in robustly. Then add the remaining whites in thirds, folding them in carefully to avoid losing the air.
5. Line a Swiss roll tin with baking parchment, leaving a generous overhang at the ends and sides, and folding the parchment into the corners to help the paper stay anchored.
6. Pour in the cake mixture and bake in the oven for 20 minutes. Let the cake cool a little before turning it out onto another piece of baking parchment. If you dust this piece of parchment with a little confectioners' sugar it may help with preventing stickage, but don’t worry too much as any tears or dents will be covered by icing later. Cover loosely with a clean tea towel.

Coffee Buttercream

4 large egg whites
1 cup sugar
24 tablespoons (3 sticks) unsalted butter, softened
2 tablespoons instant espresso powder
2 tablespoons rum or brandy

Whisk the egg whites and sugar together in the bowl of an electric mixer. Set the bowl over simmering water and whisk gently until the sugar is dissolved and the egg whites are hot. Attach the bowl to the mixer and whip with the whisk on medium speed until cooled. Switch to the paddle and beat in the softened butter and continue beating until the buttercream is smooth. Dissolve the instant coffee in the liquor and beat into the buttercream.

Unwrap the cake. Trim the ends on the diagonal, starting the cuts about 2 inches away from each end. Position the larger cut piece on the buche about 2/3 across the top. Cover the buche with the reserved buttercream, making sure to curve around the protruding stump. Streak the buttercream with a fork or decorating comb to resemble bark. Transfer the buche to a platter and decorate with the mushrooms.

Meringue Mushrooms

2 large (60 grams) egg whites, room temperature
1/4 teaspoon cream of tartar
1/2 cup (100 grams) superfine (caster) white sugar

Line two baking sheets with parchment paper. Have two pastry bags ready (one for piping the caps and stems and one for gluing them together). Fit one small pastry bag with a number 3 (1/16 inch diameter) (.2 cm) round plain tip (used to glue the stems and caps together) and one large pastry bag with a number 6 (1/2 inch diameter) (1 1/4 cm) round plain tip (for stems and caps). Fold down the tops of the bags to form a deep cuff on the outside and place each bag in a tall narrow glass for support. This will make it easy to transfer the meringue to the pastry bags.

Preheat oven to 200 degrees F (100 degrees C) and place 2 oven racks in the upper and lower thirds of the oven.

In bowl of electric mixer, at moderately slow speed, beat the room temperature egg whites until foamy. Add the cream of tartar and beat at medium speed until soft peaks form. Continue beating (increasing speed to high), gradually adding the superfine sugar, until the whites are very stiff and glossy. (You want to make sure that the sugar has dissolved completely - to test rub a little of the meringue between your fingers.)

With a rubber spatula place approximately 1/4 cup of the meringue in the pastry bag with the small tip (used to glue the caps and stems together). Place the remainder of the meringue in the large pastry bag.

To Pipe Caps: Holding the pastry bag upright and close to the parchment paper, pipe the meringue with even pressure, into even rounds building up the meringue to form a 2 inch (5 cm) round that is about 1 inch (2.5 cm) high. Sharply twist the bag and stop the pressure as you slowly move the tip off the meringue. Try to make the top as smooth as possible but use a wet fingertip to smooth out any bumps.

To Pipe Stems: Holding the pastry bag upright and close to the parchment paper, pipe the meringue with even pressure, into a cone-shape, making the base of the stem a little larger than the top. The stem should be about 1 inch (2.54 cm) high. Try to keep the stems as straight as possible. Some of the stems may fall over on their sides during baking, so it is a good idea to make extra.

Bake the meringues for approximately one hour, or until the mushrooms are firm enough that they can be lifted from the baking sheet without sticking. Rotate the baking sheets from top to bottom and front to back (about three quarters of the way through) to ensure even baking.

Remove from oven and with a small sharp knife, make a small hole in the middle of the underside of each mushroom cap. Using the small pastry bag fitted with the 1/l6 inch tip, pipe a little bit of meringue in the hole and gently press the top of the stem into the hole.

Place the mushrooms, caps down, on a parchment lined baking sheet and return to oven for about 15 - 30 minutes, or until the mushroom are dry. Remove from oven and lightly dust the tops of the mushrooms with cocoa powder. Use a small pastry or paint brush to smudge the cocoa powder, if desired.

Store in an airtight container for several weeks.

Makes about 24 - 30 mushrooms (depending on size)