The January 2011 Daring Bakers’ challenge was hosted by Astheroshe of the blog accro. She chose to challenge everyone to make a Biscuit Joconde Imprime to wrap around an Entremets dessert.
An entremet is a layered dessert wrapped in a Bisuit Joconde Imprime. The Biscuit Joconde Imprime is itself, in two parts, a Joconde Sponge and a Joconde-Décor Paste. Astheroshe provided a recipe, which I scaled down and altered slightly.
34 g blanched almonds (originally almond flour)
30 g 10x sugar (powdered, icing, or confectioners' sugar)
10 g pastry flour (originally cake flour)
60 g whole eggs (two large)
36 g egg white (two whites)
pinch (0.1 g) cream of tartar
4 g granulated sugar
12 g unsalted butter, melted
Place the almonds, 10x sugar, and flour into the work bowl of a food processor and process until finely ground. Sift into a bowl, then add the whole eggs, mixing until blended. Whip the whites to stiff peaks with the granulated sugar. Add a scant third of the whites to the batter to loosen, then gently fold in the remaining whites, avoiding deflation. Gently fold in the melted butter and set aside.
40 g unsalted butter, softened
40 g 10x sugar
40 g egg whites (2-3 whites)
34 g pastry flour
12 g cocoa powder
Cream the butter and sugar until light and fluffy, then beat in the egg whites until combined. The whites and butter will not completely combine, but so long as the butter pieces are quite small you'll be fine. Sift together the flour and cocoa powder, then fold into the butter and egg mixture.
Now for the fun part. Turn a sheet pan over (bottom-side up) and lay a Silpat on it. Spread the paste onto the Silpat rather thinly--no more than ¼" thick. Make a pattern in the paste using whatever tools you might have, then put the whole thing in the freezer. Be sure the pattern goes all the way down to the Silpat--you will flip the whole thing over to reveal the presentation side later.
Begin preheating your oven to 475°F at this point. When the oven is hot--no less than 15 minutes--the paste should be frozen solid. Remove the sheet pan with the paste on it from the freezer. Pour the sponge batter onto the paste and spread it out, making sure to fill in all the pattern you made in the paste. Pop it in the oven and set your timer for 5 minutes. The recipe provided suggested baking time of 15 minutes, but mine was done in 10. Rotate after the first 5 minutes to ensure even baking. After the second five minutes test the Joconde by pressing lightly with a fingertip. If the cake springs back it's done. If not, close the door and wait a minute or two before checking again.
While the cake is baking, lay out a sheet of parchment paper on a work surface and dust the paper with 10x sugar. Once the cake has finished baking, let it cool just until you can stand to handle the Silpat. If you wait too long it will harden and you'll have a rough time getting it off the Silpat. As soon as you can handle the Silpat, flip the cake over onto the parchment paper and remove the Silpat.
Carefully trim the cake so that it has square corners and straight edges. Then cut it into strips. Remember the carpenters' rule: measure twice, cut once. Use a straight edge to guide your sharpest knife.
Now, prepare your mold. Lay some parchment paper on top of a very flat sheet pan or other moveable flat surface, then cover with a large sheet of plastic wrap. Set your mold on top of the plastic and pull the plastic up around the mold. Cut parchment paper to fit around the inside of the mold and line the mold with the paper. Then, making sure to put the good side out, place the strip(s) of cake into the mold, pressing outward lightly so the cake conforms to the mold shape. If the cake overlaps slightly, press the edges together.
Once you've completed that, you're ready to fill the mold you've made. I used a Chocolate-Hazelnut Torte on the bottom, then spooned some Cinnamon Crème Anglaise on top. I covered that with a layer of Chocolate Mousse to hide the sauce. I molded a mousse heart, then wrapped it with a Décor Chocolate ribbon. The hearts and flowers theme was completed with a smaller heart cut from a sheet of Chocolate Décor and three chocolate roses.
Will I ever do this again? Probably not. I spent approximately twelve hours over three days to make this. On the other hand, if it weren't for the Daring Bakers' Challenge, I probably wouldn't have taken the time to recover my award-winning Chocolate-Hazelnut Torte recipe, which I'll post tomorrow.