Sunday 21 October 2007

Happy Birthday Dad!

Its my dad's birthday together and since I can't spend it with him personally, I'm taking the opportunity to wish him "Happy Birthday" with this cake that I made for him. Like me, my dad has a sweet tooth. (Unlike me, though, my dad has, for most of his life, been blessed with an amazing metabolism which means that it takes a quite a lot for him to put on any weight.) As such, I'm sure he would love this cake which is made of dark chocolate cake layers, a decadent white chocolate filling and then glazed with a generous layer of thinned dark chocolate ganache. Appropriately, the cake is called Blanc et Noir.

Although the cake has quite a few components to it, it is a relatively easy cake to make. The trickiest parts are handling the cake layers as they tend to be very moist and delicate, and getting the glaze to go on smoothly. Unfortunately, although I managed to cover the whole cake, I had a few small air bubbles on the surface of my glaze which though not fatal, does slightly mar the appearance of the cake. This is somewhat made up for by the marbling effect that is created with the white chocolate on the dark glaze - an easy technique that produces impressive looking results.

Since I can't share the cake with you, Dad, in person today, I'll make this for you another time. Hopefully, it'll turn out perfect. In the meantime, M and I have been enjoying this incredibly rich cake all of today.

Happy birthday again, Dad! I hope you're having a great day.

Blanc et Noir
From Pure Chocolate

White-chocolate ganache filling:
1/2 cup heavy cream
8 oz white chocolate, finely chopped

Noir cake layers:
8 oz semisweet chocolate, finely chopped
1 stick unsalted butter, room temperature
5 large eggs, separated
1/2 cup plus 1 tbsp sugar
Dark-chocolate ganache glaze

White chocolate for writing:
2 oz white chocolate, roughly chopped
2 tsp vegetable oil

to make the filling
In a saucepan, heat the cream over medium-high heat just until it begins to boil. Remove from the heat and add the white chocolate, stirring until the chocolate is smooth and melted. Pour into a small bowl and cover with plastic wrap touching the surface to prevent a skin from forming. Let the ganache set up at least 12 hours or overnight at room temperature.

to make the cake

Position a rack in the middle of the oven and preheat the oven to 300F.

Lightly butter a 9-by-13-inch quarter sheet pan and line with parchment paper. Then lightly butter the parchment paper.

In a double boiler melt the chocolate over low heat. Remove the boiler top when the chocolate is nearly melted and continue stirring until completely smooth. Add the softened butter in 3 parts, stirring until no visible traces of butter remain. (If the butter begins to melt and separate, stop and allow the chocolate more time to cool.) The finished mixture should be glossy and smooth. Set aside to cool until the mixture is the consistency of softened butter. Briefly return to the double boiler if it begins to thicken too much.

In a mixer fitted with the whisk attachment, whisk the egg yolks with half the sugar at medium-high speed, increasing to high speed until pale yellow and tripled in volume, 5 to 6 minutes.

Remove the bowl from the mixer. With a rubber spatula fold in the melted chocolate mixture. The mixture should be smooth and glossy.

Clean the whisk and in another clean bowl begin whipping the egg whites on medium-high speed, increasing the speed and allowing them to become quite frothy. Slowly add the remaining sugar and continue whipping until the peaks are stiff and creamy.

Lighten the chocolate mixture by quickly folding in a quarter of the whites until smooth and no traces of white remain. Then gently fold in the remaining whites in 3 parts, trying not to overmix and lose the volume. Evenly spread the batter into the prepared pan. The pan will be two-thirds full.

Bake for 20 to 25 minutes. The cake will rise above the edges of the pan, and a light crust will form on top. A cake tester inserted in the center will have a few moist crumbs.

Let the cake cool in the pan at room temperature for 10 minutes. Then chill until thoroughly cold, 4 hours or overnight. Wrap tightly with plastic wrap if chilling for longer than 4 hours. (The layer can be wrapped in plastic once cooled and placed in freezer up to a week prior to assembly.)

to assemble the cake
Have ready the white-chocolate ganache filling.

To remove the well-chilled cake from the pan, run a thin-bladed knife around the edges. Place the bottom of a baking sheet over the cake and invert. Remove the parchment paper.

Place the filling in a mixing bowl. It should be the consistency of softened butter. (If not thick enough, stir and let sit longer to thicken.) With a whisk attachment or using a hand-mixer, mix on high speed until the ganache is lighter in colour and texture and soft peaks form, 2 to 4 minutes. Stop several times and scrape down the side of the bowl.

Using a ruler and the tip of a paring knife, mark the cake in thirds across its width. Cut the cake with a serrated blade into 3 approximately 4-inch-wide sections.

Place one chilled layer of the cake on the serving plate or on a 4-by-8-inch cardboard cake board. With a metal spatula, spread half of the white ganache filling on the layer. Top with the second chilled cake layer and spread with the remaining filling. Top with the last chilled cake layer.

Using a thin-bladed knife, trim the sides of the cake. Let set in the refrigerator at least 1 hour.

to finish the cake

Make the dark-chocolate ganache glaze.

Pour about 1/4 cup of the glaze into a small bowl and place in the refrigerator to chill for approximately 25 minutes. Set aside the remaining ganache to cool about 30 minutes, gently stirring occasionally until it thickens and ribbons off the end of the spatula, 80-85F.

Meanwhile, make white chocolate for writing.

to make writing chocolate
In a small bowl over simmering water, melt the chocolate. Remove from the heat, add the vegetable oil, and stir with a spatula until smooth. Set aside.

With an offset spatula, thinly coat the top and sides of the finished cake with the 1/4 cup chilled ganache glaze. Transfer to a cooling or pouring rack positioned over a rimmed baking sheet.

Slowly and evenly pour the rest of the glaze around the sides of the cake, being careful to cover all the corners. Then pour the remaining glaze down the center using a metal spatula to spread the glaze evenly over the top, letting the excess run down the sides. Before glaze sets, decorate.

Pour the writing chocolate into a small parchment paper cone. Pipe 3 thin white parallel lines, 1/4 inch apart, lengthwise, down the center of the cake over the soft glaze. Working quickly, with a toothpick draw small figure eights crosswise through the ganache and white stripes all along the cake's length.

Chill for 1 to 2 hours to set. Remove half an hour before serving. Can be stored in the refrigerator for up to 3 days.

serves 12 to 18


Deborah said...

What a gorgeous cake!!

eatme_delicious said...

Wow that cake looks amazing. I've never made anything with white chocolate ganache before. This cake sounds like a great place for me to start!

The Caked Crusader said...

Beautiful cake - I think it would make a lovely dessert!