Chocolate Cake with Lemon Mousse

Instructions

• 1
  The cake base is baked in a water bath, so a silicone mold has proven to be the best. Line its bottom with baking paper. A classic springform cake pan must be wrapped on the outside with several layers of aluminum foil to prevent water from getting in during baking. Use a pan with a diameter of 20 to 23 cm.
• 2
  Separate the eggs into whites and yolks. Whisk the yolks with sugar until a firm foam forms, whisking at high speed for at least 5 minutes; the foam will significantly lighten during this time. Finally, briefly whisk in the sifted cocoa into the mixture. Separately, whisk the egg whites with salt until stiff peaks form, then gently fold them spoon by spoon into the cocoa mixture.
• 3
  Pour the batter into the prepared pan, place it in a deeper, taller baking tray, pour boiling water into the tray, and bake for 35 to 40 minutes in an oven preheated to 170°C with convection. After baking, let it cool in the pan. The batter will rise significantly during baking but will fall again during cooling.
• 4
  The mousse is quite tart; if you prefer sweeter desserts, add more sugar.
• 5
  Soak the gelatin in cold water and let it swell. Before use, it should have the consistency of a crumpled plastic bag.
• 6
  Boil the lemon juice, zest, and half of the sugar until the sugar dissolves. Whisk the egg yolks with the other half of the sugar for 5 minutes until foamy. Then, while continuously whisking at the highest speed, slowly pour the lemon juice into the foam in a thin stream. Transfer the entire mixture to a saucepan with a thick bottom and bring it to a boil over low heat, stirring constantly with a whisk. It is necessary to stir quickly because the mixture tends to burn. When the mixture starts to boil, immediately remove it from the heat, take 1 tablespoon into a bowl, and dissolve the gelatin in it, from which you have previously squeezed out excess liquid. The gelatin must dissolve completely.
• 7
  Whisk the remaining mixture again at the highest speed until it increases in volume and stiffens, whisking for approximately 10 minutes. Carefully fold the dissolved gelatin and the whipped cream, which you have previously whipped separately, into this firm mousse.
• 8
  Remove the cooled cake base from the cake pan and peel off the baking paper. Place the base on a serving platter and enclose it in a cake ring. Spread the lemon mousse over the base, smooth the surface, and chill in the refrigerator for several hours, or even overnight. Before serving, decorate with candied lemon zest.
• 9
  Grate the zest from one untreated lemon into thin strips using a peeler. In a small saucepan, dissolve 2 tablespoons of granulated sugar in 1 dcl of water, add the lemon zest, and simmer it in the sugar water for 10 minutes. Afterward, let it dry on a paper towel.