European Style Flourless Lemon-White Chocolate Cake

Classic European cakes do not use leavening agents and are made from ground nuts, not flour (though small amounts of flour are sometimes added as a binding agent). The Lemon - White Chocolate cake described in this Instructable follows this tradition. It is also fairly straightforward to make and would be a good candidate if you want to try your hand in the art.

The cake is a balance of sweet and sour. Sourness is provided by copious amounts of lemon curd. The cake body and a simple heavy cream/white chocolate frosting provide balance.

The cake uses a grand total of 16 eggs, which was unheard of in the old times. However, half the eggs are used in the lemon curd, so the cake batter is no richer (or at least not much richer) than many other recipes.

Yield is 12 generous servings. It's best prepared a day in advance, so that the flavors have a chance to blend overnight in the fridge. However, since there are no thick layers of filling that have to set, it can be happily devoured immediately upon completion.

I wrote this for people who are new to making cakes, so the instructions are quite detailed and there are a lot of photographs. If you'd rather have just the recipe, see the attached PDF.

I am entering this Instructable into the Baking Speed Challenge. If you like the recipe, I'd appreciate your vote.

Lemon Curd:

• 8 lemons
• 150 g sugar
• 5 egg yolks
• 3 whole eggs

Since we'll grate the lemon peel, I use organic lemons.

Cake body:

• 200g sugar
• 8 eggs, separated

400g ground nuts or almond flour

You can easily use ground walnuts, pecans, hazelnuts or almonds instead of the almond flour. I often use almond flour because blanching almonds is cumbersome and almonds are also somewhat hard to grind. If you decide to grind your own almonds and skip blanching, the cake will have darker color and a smidge stronger taste.

If you use hazelnuts, either buy roasted or, better, roast your own - 15min or so at 360F, shaking the pan at halfpoint. Pile the hazelnuts in a dish towel and rub them to remove most of the skins. Hazelnut flour is also available in stores, but I found it often to be slightly rancid.

Grind the nuts in a nut grinder - small hand grinders can be found cheaply and you'll get a more consistent grind. However, a food processor can be used in pinch.

Frosting:

• Pint of heavy cream
• 170g white chocolate

Since the chocolate is not heavily processed in this recipe, use good quality if you can.

Equipment:

Two 9" (22cm) springform pans. You can fit all the batter into one pan, but you might need to bake it a little longer and it will be harder to cut the cake into layers. If possible, use nonstick springform pans. Cut a silicone baking liner or parchment or wax paper into rounds and put it on the bottom of each pan - it will help when handling the cake. I have two rounds from a fairly sturdy silicone liner that I've been using for years.

It helps to have a stand mixer for whipping the egg whites, but a hand mixer will work as well. I use a stand mixer for the whites and a hand mixer for everything else.

Separate five eggs and reserve the whites for another use. The yolks and the whole eggs should go into a heatproof bowl. Whisk the eggs until fairly uniform - you don't wand visible egg whites remaining as they'll just coagulate during the cooking.

Wash the lemons in hot water and dry them with a kitchen towel. Zest the lemons.

Squeeze the lemons and put all the juice into a pot. Since we'll strain the finished lemon curd, there is no need to remove the pulp. You should have close to a pint of juice. Depending on the size and quality of the lemons, you may need more or fewer than eight. The lemons I used were really large but turned out pretty pitiful - thick rind and some of them were pretty dry. Nice juicy lemons of that size would have yielded too much juice, but this way there was about enough.

Add the zest and sugar to the pot and heat on medium until the sugar has dissolved and the mixture is hot. Whisking steadily, slowly pour the lemon mixture into the eggs. Return the mixture to the pot and cook on low heat, stirring steadily with a wooden spoon until it starts to thicken.

It's OK if the curd is not quite set, it will continue to thicken after being removed from the heat. Do not let boil.

Strain the curd into a heatproof bowl, cover with plastic wrap, cool and refrigerate.

Preheat the oven to 300F.

Separate the eggs. Add about two thirds of the sugar to the yolks and beat until pale yellow and very thick. Add the nuts and fold them in. The batter will be very stiff.

Beat the egg whites. I used a stand mixer, but a hand mixer will work as well, though it may take a little longer. Use the highest speed setting on your mixer. When soft peaks form, pour the remaining sugar in a thin stream into the egg whites, with the mixer running. Beat until stiff, but not dry.

Fold the egg whites into the batter in four batches. Because the batter is so stiff, the first couple of batches will be pretty hard going, but the resulting batter will be soft and easy to work with.

Put the liner (or parchment, or wax paper) round on the bottom of each pan. Divide the batter equally between the pans, smooth with the spatula and then shake to get an even surface.

Bake for 35 minutes or until an inserted toothpick comes out dry. Let the cakes cool completely in the pan.

Coarsely chop the white chocolate. As always, having good quality chocolate is wonderful, but hey, mediocre chocolate is better than no chocolate! I've made plenty of cakes while a penniless graduate student.

Melt the chocolate in a microwave or a double boiler or in a bowl suspended over a pot of simmering water. White chocolate is finicky and burns easily, so keep the heat low and take your time. Cranking your microwave to 11 will lead you to grief - I'll use setting 4 to start and 3 when close to the end. Let the chocolate cool.

Whip the heavy cream. When it starts to thicken, but long before it becomes actual whipped cream, add the melted chocolate in a thin, steady stream with the mixer running. Lacking a third hand, I usually stop the mixer to scrape the last of the chocolate into the cream.

Once the chocolate is added, the cream will stiffen very quickly and is easy to overbeat. In fact, if you look at my finished cake carefully, you'll note that the frosting has a bit of grainy texture, meaning it has been overbeaten a smidge. Since we'll be using the whipped cream just to frost (and not as a filling between the layers) it doesn't have to be too stiff.

Unmold the cakes from the springform pans. If the centers have sunk, trim the tops level using a sharp knife.

Invert one cake onto a serving platter. Using a long knife, cut the cake into two layers. Using a knife and a spatula, remove the top layer - the liner will make the layer sturdier so it doesn't break apart.

Spread about a quarter of the lemon curd onto the first cake layer. Top with the second layer. It helps to return the layer in the same orientation relative to the first layer when it was removed - it will help keep the cake level. Peel the liner off.

Spread another quarter of the lemon curd on top, then invert the second cake on top. Repeat the process with the second cake by cutting it, removing the top layer, spreading the lemon curd and returning the top layer. Again remove the liner.

Spread the remaining curd on top and the sides of the cake. This will yield a little thinner layer of curd, making the cake easier to frost. We are using the curd as a crumb coat.

Frost the cake. It helps to first frost the sides, since otherwise the curd is prone to leaking through the frosting. Cake decorating is not my strong suit, so your cake will quite likely look better than mine!

The cake can be enjoyed immediately, but will taste better if left overnight in the fridge. Enjoy!