This is another chocolate log cake made for my younger brother's party. I was pretty glad that I get to practice on my rolling of swiss roll. This time round, I made sure that the sponge was rolled tightly and it there were no cracks after rolling. However, it turned out to be tightly rolled on one end but not so much on the other end. Nevertheless, it served as a good practice.
After slicing of about one-fifth of the original roll and placing it at the side of the main roll, this is how the log cake should look like before coating with buttercream (coating with chocolate ganache should work too).
There is lesser of a fuss when it comes to doing the frosting for the log cake as compared to that for layer cakes. There is no need for the frosting to be mirror-smooth. After doing the 'tree bark' effect using the tines of a fork, the surface willl look rugged anyway.
To ensure that the buttercream do not make a mess on the cake board, I chucked rectangular slips of baking paper under the log cake. After the frosting is done, the papers are carefully removed and the cake board remained clean.
As depicted in the above picture, the frosting did not make a mess on the cake board, saving the hassle to wipe away any frosting that has stained the board. This trick of using rectangular slips of baking paper picked up from Rose Levy Beranbaum is useful when frosting layers cake too.
Dust the completed log cake with snow powder/ icing sugar to give it a simple snowy feel. Alternatively, decorate it with xmas figurines, white chocolate curls or coloured dragees.
I am submitting this post to Aspiring Bakers #2: Christmas! (Dec 2010)
Chocolate Log Cake ( Sponge recipe adapted from Elegant Swiss Rolls by Kevin Chai, chocolate buttercream recipe adapted from Chocolate Ephiphany by Francois Payard)
Serving size: 10 slicesTaste and texture: Cake base is soft, moist and *slightly chewy. Chocolate buttercream is smooth and chocolatey.
Equipment and materials:
1) 12 x 12 inch pan or 10 x 14 inch pan
2) Stand electric beater/ handheld electric beater
4) wire whisk/balloon whisk
5) Mixing bowls
6) Heatproof bowl
7) Wire rack
8) Flour sieve
9) Parchment/baking paper
10) Brush for oiling pan
11) Weighing scale
12) 10 x 10 inch square cake board
13) 10 x 10 inch square cake box
250g whole eggs, room temperature (about five 55-60g eggs)
90g caster sugar
95g plain flour (cake flour will do as well)
20g cocoa powder
70g unsalted butter, melted
Swiss Meringue Chocolate Buttercream:
125g egg whites, room temperature
85g granulated sugar
225g unsalted butter, softened but still cold
50g cocoa powder (add more if desired to up the chocolate factor)
Making Cake Base:
Pre-preparation: Line the swiss roll tin with baking/parchment paper. Preheat oven to 200 degrees C.
Combine dry ingredients: Mix the flour and cocoa powder together in a large bowl to ensure they are evenly distributed.
Beating whole eggs: In a mixing bowl, beat whole eggs with 90g caster sugar on medium speed untill eggs are well aerated and have expanded about 4-6 times in volume. The beaten eggs should be thick and fluffy. When the beater is lifted, the falling batter leaves a ribbon-like trail that does not level with the rest of the batter immediately (takes about 20 seconds before levelling with the bulk of the mixture). This is know as the 'ribbon stage'. Continue to beat the foamed eggs on low speed for abother 2-3 minutes. This is to stabilize the egg mixture.
Folding dry ingredients into beaten eggs: Sift one-third of the dry ingredients into beaten eggs. Fold using a balloon whisk, gently and gradually, untill the dry ingredients are incorporated. Repeat the same for the remaining two-thirds of the dry ingredients. Scrape sides and bottom of bowl with a flexible spatula every now and then to incorporate flour that is stuck to the sides and that which have sunk to the bottom. We want the beaten eggs to deflate as little as possible in the folding process.
Adding the butter: Scoop a small portion of the flour-egg batter and mix it with the melted butter in a medium bowl until smooth. This makes it easier to fold the butter into the main flour-egg batter. Add this butter mixture back to the main bulk of the flour-egg batter. Fold gently to obtain a evenly mixed foamy batter.
Baking the cake: Pour cake batter into lined tin and bake at 200 degrees C for 8 to 12 minutes. The cake is done when a toothpick inserted at the middle comes out clean. The top skin of the cake should be springy when pressed and moist and sticky to the feel. Once done, remove cake tin from oven and place on a wire rack. Cover the surface with a sheet of aluminuim foil or baking paper to maintain the moistness. Take care not to overbake the cake. It will turn dry if slightly overbaked.
Preparing the Swiss Meringue Chocolate Buttercream:
Dissolve sugar in egg whites: Place 125 egg whites and 85g granulated sugar in a heatproof bowl. Sit the heatproof bowl on a saucepan filled with water. The base of the bowl should not be in contact with the water. Bring the water in the saucepan to a slight simmer. Use a balloon whisk and stir the egg whites and sugar constantly until the sugar has fully dissolved (no gritty feel when rubbed with your fingers) and the mixture is warm to the touch (test by inserting a finger). Take care not to scramble/cook the egg mixture.
Beating egg whites: Remove the heatproof bowl and beat the warm egg white mixture on medium high speed to obtain stiff peaks using an electric beater. At stiff peaks, the beaten egg whites will not budge when bowl is overturned. When the beaters are lifted from the beaten egg whites, the surface of the egg whites should form stiff upright peaks (not drooping peaks). The beaten egg whites should be cool to the touch (room temperature), not warm like when it was removed from the saucepan.
Adding butter and cocoa: Beat in 225g butter into the beaten egg whites in 3 batches, ensuring each batch is incoporated before adding the next. The mixture will be watery at one point in time. Just continue beating and the mixture will become sturdy, creamy and fluffy. Lastly, sift in 50g cocoa powder and continue beating to obtain a smooth chocolate buttercream.
Turning the cake out: Turn the baked sheet cake onto a piece of baking/parchment paper. Slowly peel off the attached baking/parchment paper from the cake.
Rolling the cake: Apply half the prepared buttercream over the surface of the sheet cake. With the shorter side/breadth facing you (if using 10 x 14 inch pan), roll the cake up tightly to form a swiss roll.
Covering cake with buttercream: Place swiss roll on a 10 x 10 inch square cake board. Slice one-fifth of the log and position this sliced portion at the side of the main roll. This is to give the log cake a branched shape. Chuck rectangular slips of baking paper under the log cake.
Apply a thin layer of chocolate buttercream over the log to seal in the crumbs. Cover the entire log evenly with chocolate buttercream. There is not need for the buttercream to be very smooth. Use the tines of a fork to scratch along the surface of the buttercream to give a 'tree bark' effect. Dust with snow powder/icing sugar and decorate as desired. Carefully remove the rectangular slips of paper.
1) Store completed log cake in the refrigerator in a 10 x 10 inch cake box (with 10 x 10 inch square cake board). Allow it to soften at room temperature for 20 minutes before serving.
2) Decorate the log cake with xmas ornaments like santa claus, reindeers and snowman figurines; green/silver/golden mini christmas trees; red and green mini dragees/sprinkles, gold and silver mini/normal dragees; white chocolate curls etc. Most of these can be obtained from baking supply stores (Phoon Huat, Sun Lik etc).
3) I have reduced the amount of sugar by a lot. Do not be tempted to further reduce the sugar.
4) Use good quality cocoa powder like Valrhona for the best results.
5) Chocolate ganache may be used to cover the log cake instead. Alternatively, plain whipped cream may also be used.
6) 200 Degrees C ensures that the sponge sheet is baked at a short time while less water content is evaporated, keeping the cake moist. If sponge cake is overbaked and turns out dry, brush it with a simple syrup to moisten it. A simple syrup consists of equal mass of water and sugar.