Black and White Chocolate Cake

Last week I needed to bring dessert over to a friend's house for after dinner drinks.  I was originally going to make a cheesecake but my local grocery store caught on fire!   No one was hurt but everything in the store had to be thrown out and the store was closed for a day. Since I could not run out to my neighborhood store I had to wait until the next morning to send Mr. Apron to a store further away to get  ingredients.  This delay also meant I had to change what I was going to make. I find cheesecake to be best when it sits overnight, and I did not want to risk having runny cheesecake by not having enough time for it to set.

As an alternative I decided to try Dorie Greenspan's Black and White Chocolate Cake. For a second choice dessert this cake came out really well.  The dark chocolate filling is incredible1  It is like a chocolate pastry cream. The cake itself seems a little thin, for some reason it works cut into four layers, but I think I would have preferred a bit more actual cake.

I read other review of the original recipe and several others said how they ran out of the white chocolate frosting when assembling the cake, but had extra dark chocolate.  Knowing that I typically need a lot of frosting, I altered the original recipe and used only the dark chocolate for the filling and saved the white chocolate cream for the outside.  I don't think it took away from the cake at all.  And being a big fan of dark chocolate I loved having only dark on the inside.  I think if I were to make this again, I would double the white chocolate cream to make sure I had enough for the filling and the frosting.

Black and White Chocolate Cake

For the cake:

2 cups cake flour
2 tsp baking powder
1/8 tsp baking soda
1/4 tsp salt
1 1/4 (10 Tbsp) unsalted butter, at room temp
1 cup sugar
3 large eggs
1 large egg yolk
1 tsp vanilla extract
3/4 cup buttermilk

Dark chocolate cream:

2 cups whole milk
4 large egg yolks
6 Tbsp sugar
3 Tbsp corstarch, sifted
1/4 tsp salt
7 oz. bittersweet chocolate, melted
2 1/2 Tbsp unsalted butter, cut into 5 pieces, at room temp

White chocolate whipped cream:

6 oz. premium quality white chocolate
1 1/2 cups heavy cream

To make cake: Center a rack in the oven and preheat the oven to 350 degrees. Butter two 9X2 inch round cake pans, dust the insides with flour, tap out the excess and line the bottoms of the pans with parchment or wax paper. Put the pans on a baking sheet. Sift together the cake flour, baking powder, baking soda and salt.

Working with a stand mixer in a large bowl, beat the butter on medium speed until soft and creamy. Add the sugar and beat for another 3 minutes. Add the eggs one by one, and then the yolk, beating for 1 minutes after each addition. Beat in the vanilla; don’t be concerned if the mixture looks curdled. Reduce the mixer speed to low and add the dry ingredients alternately with the buttermilk, adding the dry ingredients in 3 additions and the milk in 2 (begin and end with the dry ingredients); scrape down the sides of the bowl as needed and mix only until the ingredients disappear into the batter. Divide the batter evenly between the two pans and smooth the tops with a rubber spatula. Bake for 28-30 minutes, rotating the pans at the midway point. When fully baked, the cakes will be golden and springy to the touch and a thin knife inserted into the centers will come out clean. Transfer the cakes to a rack and cool for about 5 minutes, then unmmold, remove the paper and invert to cool to room temperature right side up on the rack.

To make the dark chocolate cream: Bring the milk to a boil. Meanwhile, in a large heavy-bottomed saucepan, whisk the egg yolk with the sugar, cornstarch and salt until thick and well blended. Whisking without stopping, drizzle in about 1/4 cup of the hot milk-this will temper, or warm, the yolks so they won’t curdle-then, still whisking, add the remainder of the milk in a steady stream. Put the pan over medium heat and, whisking vigorously, constantly and thoroughly (make sure to get into the edges of the pan), bring the mixture to a boil. Keep at a boil, still whisking, for 1-2 minutes. Remove the pan from the heat. Whisk in the melted chocolate, and let stand for 5 minutes. Then whisk in the pieces of butter, stirring until they are fully incorporated and the chocolate cream is smooth and silky. Press a piece of plastic wrap against the surface of the cream to create and airtight seal and refrigerate the cream until chilled, or for up to 3 days. Or, if you want to cool the cream quickly, put the bowl with a cream into a larger bowl filled with ice cubes and cold water and stir the cream occasionally until it is thoroughly chilled, about 20 minutes.

To make the white chocolate whipped cream: Put the white chocolate in a heat proof bowl and put the bowl over a saucepan of gently simmering water. Stir frequently to melt the chocolate evenly. Meanwhile, bring 1/2 cup of the heavy cream to a boil. When the white chocolate is melted, remove the bowl from the pan. Pour the hot cream into the melted chocolate and let it sit for a minute. Using a small spatula, stir the chocolate gently until it is smooth. Let it sit on the counter until it reaches room temperature-it can’t be the least warm when you add it to the whipped cream. Working with the stand mixer with the whisk attachment or with a hand mixer in a large bowl, beat the remaining 1 cup of heavy cream only until it holds the softest peaks. Turn the machine to high, add the cooled white chocolate all at once and continue to beat until the whipped cream holds firm peaks. Turn the whipped cream into a bowl, press a piece of plastic wrap gently against the surface to create an airtight seal and refrigerate for at least 2 hours, or up to 6 hours.

To assemble the cake: If the tops of the cake layers have crowned, use a long serrated knife and a gentle sawing motion to even them. Slice each layer horizontally in half. Place on layer cut side down on a cardboard cake round or on a cake plate. Remove the dark and white chocolate creams from the refrigerator and whisk each of them vigorously to loosen and smooth them. With a long metal icing spatula, spread enough dark chocolate cream (about 1 cup) over the cake layer to cover it completely. Top the cream with another cake layer, and repeat with 2 more layers. (You should have three layers.) Place the final layer of cake, cut side down  and frost the sides and top with the white chocolate whipped cream.  Refrigerate for at least 3 hours, or overnight.

Adapted from Baking: From My Home to Yours by Dorie Greenspan