Tempered White Chocolate Anniversary Cake {Tutorial}

Good friends of ours celebrated their 20th Wedding Anniversary last week. Since the traditional gift for a 20th anniversary is china, they took us all out to a Chinese Restaurant for an evening of eat-as-much-as-you-like food, great company, and karaoke! Gotta love karaoke! :)

A few weeks ago, over lunch, my friend (who's anniversary it is) showed me a photo of a cake and said: "I would love to have this cake for our anniversary. I know you can't right now, but is this a cake you could make?" I laughed, and replied, not only can I make this cake, but I have actually made it before. The photo she showed me looked like a near-identical twin to the wedding cake I had made for my brother and his wife a few years ago!

I ended up making the cake as a surprise. I finally got frustrated with sitting around all day doing nothing and decided to do some baking. I opted for only one 9" tier though, as I didn't think my arm would make it through 2 cakes.

I am pleased to say that they were very delighted with the surprise.

Making the Cake

The first thing to do is bake the cake - see my previous post for that.

While the cake is baking, prepare the

Milk/Plain Chocolate Ganache

Ingredients:

1.2kg Chocolate (400g plain chocolate, 800g milk chocolate - I love the flavour of this combination).

          It should be chopped, but I couldn't chop it, so I settled for just breaking it into blocks.

500ml Cream (I use double cream - any cream that can be whipped can be used, including Elmlea)

Method:

Place chopped chocolate into a large microwave safe bowl.

Heat the cream in a pan until just before boiling. Pour it over the chocolate. 

Shake the bowl around a bit until the chocolate all settles beneath the surface of the hot cream. Leave it to sit for a couple of minutes.

Stir the chocolate into the cream. Keep stirring until it is nice and smooth.

If you still have a few lumps of chocolate that won't melt in, pop the whole bowl into the microwave for a few seconds at a time, stirring in between, until all the lumps are gone. I had to do this a few times because of the large blocks of chocolate I was using.

Leave the ganache at room temperature to cool for a few hours, stirring it occasionally (mine took 4 hours) until it becomes thick enough to hold its shape, but easily spreadable.

The method is the same for white or dark chocolate ganache, but the ratios of Chocolate : Cream differ depending on the kind of chocolate you are using. I use the following ratios:

White Chocolate     3 : 1    Cream

Milk/Plain Chocolate    2 1/2 : 1    Cream

Dark Chocolate    2 : 1    Cream

I never make 100% Milk Chocolate Ganache because it's flavour just lacks depth.

Next, you need to make a template for the white chocolate rectangular panels. Start by measuring the thickness of your baked cakes. Then make your template as shown above:

Now make the 

Tempered White Chocolate

You will need:

500g Good Quality White Chocolate, chopped (I had a helper this time ;)

Double Boiler

Silicone Spatula

Candy / Digital Food Thermometer

Ofset Spatula

Small Spatula or Palette Knife (to cut chocolate into shapes needed)

Food safe Acetate

Boil a little water in the bottom pan of a double boiler, then remove from heat. Put 3/4 of the chocolate into the top pan and place over hot water (reserve the other 1/4 for later). Stir the chocolate as it melts. Be very careful not to get any water into the chocolate, as it will cause the chocolate to seize.

Keep heating the chocolate until it reaches a temperature of between 116-118ºF, then immediately remove the top pan from the hot water. Add a handful of the reserved chocolate to the melted chocolate and stir it in to start the cooling process. (While you are cooling the chocolate, return the pan of water to a medium heat to get it hot again.)

Keep cooling the chocolate, stirring, scraping the sides and adding in handfuls of the reserved chocolate until the temperature drops to 79-82ºF. Only add a new handful of chocolate once the previous one has completely melted. When it no longer melts in completely, but leaves lumps, stop adding unmelted chocolate (you may not use the entire 1/4 of reserved chocolate). If there are still lumps when the chocolate reaches temperature, remove them before you move on to the next step.

Return pan of chocolate to the hot water for a few seconds at a time, and stir the chocolate. You want to raise the temperature of the chocolate back up to between 86-88ºF. Don't leave it over the hot water for too long, or you will over heat your chocolate (you don't want it to go above 88ºF). Once it reaches temperature, you can start making the panels. If the temperature of the chocolate in the pan drops in temperature as you are working, just heat it again, keeping it below 88ºF.

To make the rectangular panels, pour some of the chocolate onto an acetate sheet and spread it out quite thinly with the offset spatula. You want it to be about 1.5-2mm thick.

Make sure you spread the chocolate wide enough for the template to fit onto it, and long enough to get out all the panels you need - I used 15 panels in total, though I made 18, just in case.

It is possible to make the surface smoother, but it's not necessary for this cake. The bottom side, on the acetate, will be beautifully smooth and shiny once set, and that will be outermost on the cake.

Wait for the chocolate to set to the point where it no longer looks really shiny (but don't wait too long or the chocolate will be too hard to cut).

Using a small spatula or palette knife, cut the chocolate into rectangles. I used my side scraper to judge sizes and cut straight lines.

Leave the cut chocolate to set thoroughly. It is ready when it peals very easily away from the acetate. Excess bits of chocolate around the sides of the panels can be added back to the melted chocolate and remelted (again, be careful not to heat above 88ºF).

I decided to cut some fun shapes out of some the excess bits of chocolate, once I had enough panels cut.

Set all the tempered chocolate pieces aside to set completely before peeling from the acetate.

Once the ganache is ready, sandwich the cake layers

and then coat the entire cake with the ganache. I wasn't too fussy about getting a 'perfect' finish, since it is going to be completely covered (that, and I was working with my clumsy left hand and barely usable right hand, so I doubt I could have done much better anyway!) There should be ganache left over to be piped on to the top of the cake, later.

Start attaching the tempered chocolate panels to the cake.

Spread a bit of ganache onto the back side (the rough side) of each panel to stick it to the cake, only along the side that will stick to the cake and leaving the top 1 1/2" clear, be careful not to get ganache on the side that overlaps the neighbouring panel (see image below).

Breakages are inevitable, always make a few extra pieces, just in case!

You may need to readjust the overlap of the panels to get them all to fit on evenly.

Put the remaining ganache into a piping bag with a large star nozzle and pipe swirls on the top of the cake, filling in the gaps around the sides, between the cake and the tempered white chocolate panels.

While the ganache is still soft, add the tempered white chocolate decorations.

At the last minute, I decided to paint on some gold details.

Finally, add a pretty ribbon.

Yum!