Chocolate Sponge Cake: Preheat
your oven to 450
degrees F (230 degrees C) and place the oven rack in the center of your oven. Butter,
or spray with a nonstick vegetable spray, a 17x12 inch (43x30 cm) baking pan,
line it with parchment paper, and then butter and flour the paper (or spray with
a nonstick vegetable/flour spray).
In a bowl, whisk
the flour with the cornstarch, cocoa powder, and salt.
Next, remove 1
tablespoon (15 grams) of the granulated white sugar called for in the recipe and
set it aside. It will be added to the whipped egg whites.
Then, place the
and three egg yolks, along with the remaining granulated white sugar and vanilla
in the bowl of your electric mixer, fitted with the whisk attachment (can use a
hand mixer). Beat on high speed until the mixture is thick,
pale yellow, and fluffy (this will take about five minutes). (When you slowly
raise the beaters the batter will fall back into the bowl in a slow ribbon.) Sift half the flour
mixture over the beaten egg mixture and
fold in gently with a rubber spatula, just
until the flour is incorporated. Sift the remaining flour mixture into the
batter and fold in.
In a clean bowl, with the whisk attachment, (or
with a hand mixer) beat the egg whites and
cream of tartar, on medium low speed, until soft peaks form. On high speed,
gradually add the
one tablespoon (15 grams) sugar and beat until stiff
peaks form. Gently fold a little of the whites into the batter to lighten it,
and then fold in the rest of the whites. Pour the batter into your prepared pan,
spreading evenly with an offset spatula or back of a spoon. Bake for
about 6-8 minutes, or
until set, and when the top of the cake is lightly pressed, it springs back (a
toothpick inserted into the center of the cake will come out clean).
Immediately upon removing the cake from the oven,
sprinkle the top of the cake with some powdered sugar and then invert the cake onto a clean dish towel
(the powdered sugar will prevent the cake from sticking to the towel). Remove
the parchment paper, sprinkle the top of the cake with powdered sugar, and
up the sponge cake, with the towel (this helps prevent cracking and sets the log
shape). Place on a wire rack to cool.
Frosting: Place the chopped chocolates in a medium sized heatproof bowl.
Heat the cream and butter in a small saucepan over medium heat. (Can also heat
the cream and butter in the microwave.) Bring just to a boil. Immediately pour
the boiling cream over the chocolate and stir gently (as you do not want to
incorporate too much air into the mixture) with a spoon or whisk until smooth. Set aside
until it thickens to spreading consistency (this may take a couple of hours).
Chocolate Whipped Cream: In a large mixing bowl,
fitted with the whisk attachment (can use a hand mixer), place the whipping cream,
vanilla extract, sugar, and
cocoa powder and whisk to combine. Then beat the mixture, on high
speed, until stiff peaks form.
Once the cake has cooled,
unroll, spread with the cream and then
gently roll the cake back into a log shape.
Next, cut about
a 1 - 1 1/2 inch (2.5 - 3.75 cm) diagonal
slice from one end of the cake and, using a little of the frosting, attach it to
one side of the cake (so it looks like a tree limb). Then cut a slice straight
across the cake (to make the cake even) and again, use a little of the frosting, attach it to the other
side of the cake (so you have two tree limbs). Frost the top and sides of the
cake with the remaining frosting. If you like you can run the tines of a fork
through the frosting so it looks like the "bark" of a tree. Cover and place
in the refrigerator until serving. This cake can be stored in the refrigerator
for about 4-5 days. Just before serving remove the cake from the fridge, dust
the top with powdered
sugar (for snow) and decorate with meringue mushrooms, if using.
Note: You can make
chocolate truffles from any leftover chocolate frosting. First, cover and
refrigerate the chocolate frosting until firm. Then form
into small balls and roll
cocoa powder, confectioners (powdered or icing) sugar or chopped nuts. You can use your
hands to form the truffles, a melon baller or small spoon. Truffles can
be refrigerated for a couple of weeks or else frozen for a couple of months.
Serves about 6-8 people.