The Daring Bakers' challenge: Walnut Biscuit Joconde Entremet with Mango Bavarois and White Chocolate Ricotta Cream

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.

Very challenging challenge!  The mandatory item was making the biscuit joconde imprime (pronunciation here, translation: spongecake with imprinted desing) using the recipe provided. Huh, something I've never heard about but seen some images (though I had no idea it's joconde imprime).  That's quite a challenge (I know I know I use the word in almost every sentence). And what a surprise, I'm late again! I didn't have time during the whole month but I am glad I completed it. It's very creative and that's just what I needed - I've learnt so many new things!

At first I'd like to explain what this jocond thingie is. Here's the quotation of our hostess: A joconde imprime (French Baking term) is a decorative design baked into a light sponge cake providing an elegant finish to desserts/torts/entremets/ formed in ring molds. A joconde batter is used because it bakes into a moist, flexible cake. The cake batter may be tinted or marbleized for a further decorative effect. This Joconde/spongecake requires attentive baking so that it remains flexible to easily conform to the molds. If under baked it will stick to the baking mat. If over baked it will dry out and crack. Once cooled, the sponge may be cut into strips to line any shape ring mold. A joconde imprime is the outside cake wrapper of the Entremets dessert.

And what is an entremet (literally meaning "between servings", more appropriate here is a dessert)? Entremets (French baking term)- an ornate dessert with many different layers of cake and pastry creams in a mold, usually served cold.

Okay, so I know what to do as the base for my entremet, but what shall I put inside? So many possibilities, variations,diffrent ingredients, layers etc. However, time is my biggest enemy so I decided to make two different fillings. Mango Bavarian Cream and White Chocolate Ricotta Cream.

A bavarian cream (or bavarois) is a custard thickened with gelatin. It is supposed to be a swiss invention and it resembles the well-known pastry cream. It can be used either as a dessert or as a filling for a cake or something similar. I love mangoes in any form and this was my very first choice for a cream. I searched the net for some inspiration and found some great here - on a great blog by Ambika.

As for the second cream, I'm addicted to ricotta. Yes! I could eat pounds and pounds of it every now and then. So thick, creamy, creamy and once again creamy, delicious cheese with neutral taste...heaven. Preparation time for this cream is really just a matter of seconds. Extremely easy, fast and exquisite.

Okay, theory's behind us. It's time to get to the practice.

Ingredients:
Décor Paste:
40g butter
40g powdered sugar
40g egg whites
34g cake flour
12g cocoa powder
Joconde (spongecake):
85g extra finely ground walnuts
75g powdered sugar
30g cake flour
150g eggs (approx. 3 large)
90g egg whites (approx. 3 large)
10g caster sugar
Mango Bavarois:
500g mango puree (or 2 large mangoes)
100g powdered sugar (or less/more to taste)
2 tbsp fresh lemon juice
15g gelatin powder
230g (240ml) whipping cream
White Chocolate Ricotta Cream:
500g ricotta
155g white chocolate
20g powdered sugar (less/more to taste)

Directions:
Décor Paste: Sift the flour and cocoa powder together. Cream butter and sugar until light and fluffy. Gradually add egg whites. Beat continuously. Fold in sifted flour-cocoa mixture. Spread a thin even layer of décor paste approximately 1/4 inch (5 millimeter) thick onto silicone baking mat or parchment paper with a spatula, or flat knife. Place mat on an upside down baking sheet (33x46cm). The upside down sheet makes spreading easier with no lip from the pan. Make horizontal /vertical lines (you can use a knife, spatula, I used cake/pastry comb). Slide the baking sheet with the décor paste into the freezer. Freeze hard. approx 1-2 hours.
Joconde (spongecake): Sift confectioner’s sugar and cake flour and mix with ground walnuts. On medium speed, add the eggs a little at a time. Mix well after each addition. Mix until smooth and light. In a clean mixing bowl whip the egg whites and white granulated sugar to firm, glossy peeks. Fold in one third reserved whipped egg whites to almond mixture to lighten the batter. Fold in remaining whipped egg whites. Do not over mix. Preheat your oven to 250ºC. Remove the décor paste from freezer. Quickly pour the Joconde batter over the design. Spread evenly to completely cover the pattern of the décor paste (but the layer of joconde batter shouldnot be too thick).  Put into the oven and immediately lower the temperature to 200C and bake until the joconde bounces back when slightly pressed, approx. 10-15 minutes. You can bake it as is on the upside down pan. Yes, it is a very quick bake, so watch carefully every 5 minutes to ensure it's not burnt. Cool for 5 minutes. Flip cooled cake on to a powdered sugared parchment paper. Remove silpat. Cake should be right side up, and pattern showing! (The powdered sugar helps the cake from sticking when cutting.)
Assembling: Place a spring form pan ring, with the base removed, on a plate you want to serve your cake at. Line the inside of the ring with a curled piece of parchment paper overlapping top edge by ½ inch. CUT the parchment paper to the TOP OF THE MOLD. It will be easier to smooth the top of the cake. My spring cake form is 6cm high, diameter is 22cm. Trim the joconde (spongecake) of any dark crispy edges. You should have a nice rectangle shape. Measure the height of your form and cut the joconde into equal strips of height and lenght (use a very sharp paring knife and ruler). Make sure your strips are cut cleanly and ends are cut perfectly straight. Press the cake strips inside of the mold, decorative side facing out. Once wrapped inside the mold, overlap your ends slightly. You want your Joconde to fit very tightly pressed up to the sides of the mold. Then gently push and press the ends to meet together to make a seamless cake. The cake is very flexible so you can push it into place. You can use more than one piece to “wrap “your mold, if one cut piece is not long enough. Use the rest of your joconde as a base - cut out a circle (a bit bigger than you'd need) and put into the mold lined with strips. Push a little to make it fit perfectly. The mold is done, and ready to fill. Now spread evenly the mango bavarois into your prepared lined mold. Place into freezer and freeze for 1-2 hours. Remove from freezer (the surface of the bavarois should be firm). Spread evenly the white choc. ricotta cream over the bavarois one (now your entremet shoudl be filled to the top) and freeze again for at least 3 hours or until the surface of the cream is firm and not runny at all. Remove from freezer and let stand for about 1 hour or until the entremet defrosts. Remove the ring form. Decorate as desired (I used stabilized whipped cream, walnuts and dark chocolate). Serve. Then store in refrigerator (don't freeze it again).

Mango Bavarois: If using ripe mangoes, puree the mango chunks until smooth (there should be no mango pieces).  Measure 500g of puree into another bowl and stir in the sugar and lemon juice. Put 2 tbsp of the puree mixture into a small bowl. Pour 1 inch (3cm) of water in a small saucepan and bring to a bare simmer. Place 3-4 tbsp of cold water in a small heatproof bowl and sprinkle gelatin on top. Let stand for 1 minute to dissolve. Place the bowl over the simmering water and heat, whisking constantly, just until the gelatin melts, 30 secs to 1 minute. Whisk the melted gelatin into the small bowl with 2 tbsp of puree, working quickly so that no rubbery strands form. Immediately pour the gelatin-puree mixture into the rest of the puree and whisk well. There should be no rubbery strands. Whip the whipping cream with an electric mixer until it holds soft peaks. Gently fold the whipped cream into the puree using a rubber spatula. Use immediately.

White Chocolate Ricotta Cream: Let stand your ricotta at room temperature for at least 2 hours. Break the chocolate into small lumps and put it into a heatproof bowl within a gently simmering saucepan of water until melted. Let cool until lukewarm. In a food processor, blend the ricotta, sugar, and melted chocolate until smooth (about 2-3 minutes). Use immediately.

• If you cannot buy cake flour, here's know-how for homemade one.
• This is exactly how I made the cake you can see in the photos. For the original recipes go to The Daring Kitchen.
• You can use any type of nuts for the joconde (spongecake). If usuing amonds, add 30g melted butter to the batter.
• You can make any design with the décor paste (dots, zig zags, letters, simply whatever) and you don't have to make it brown, but you can use food coloring of your choice. In this case omit the cocoa powder and increase the amount of cake flour to 44g.

Verdict:
Gosh, this was a tough one! It took one whole day to assembly, decorate, chill etc. I was worried it wouldn't set, thicken and so on, but in the end it was all right and now I'm experiencing some great food here. The creams are very light, not too sweet, creamy, luscious and really very good. The joconde is not very sweet (at least less than what I'm used to with my usual spongecake) and complements the creams very well. The unsweetened whipped cream is just the perfect final dot and dark chocolate as a decoration, well, what can I say? It's chocolate :D Even though there is almost just cream in this cake, it's very tasty and I have to say I'm quite proud of the end result and my whole family was pretty surprised to see this kind of cake. I don't think it's the type of dessert you make every weekend just 'cause you have your sweet tooth, but for special occasions it's the perfect choice (and delicious, of course :))