1Combine ground almonds, ground hazelnuts. flour and 85 gr. sugar.
2With an electric mixer beat the egg whites, when they start becoming opaque add 45 gr. sugar and lemon zest. Keep beating until stiff peaks form.
3Add the almond-hazelnut mixture and gently fold with a rubber spatula.
4Preheat oven to 340F.
5Spread out the batter on a baking sheet lined with parchment paper.
6Sprinkle with chopped hazelnuts and bake for about 15 minutes.
8Make chocolate mousse:
9Dissolve the gelatin in cold water, and set aside.
10With an electric mixer, beat the egg yolks and sugar.
11In a small saucepan, heat the milk until small bubbles start forming on the edge of the pan.
12Slowly pour the hot milk into the egg-sugar mixture, stir and return to the saucepan over low heat until the mixture thickens.
13Add the softened gelatin and the chocolate then whisk until well incorporated.
14Make white chocolate-lemon mousse:
15In a small bowl with cold water, dissolve the remaining gelatin. Set aside.
16Beat the egg yolks and sugar until pale.
17In a small saucepan heat the lemon juice and zest.
18Add to the egg yolk-sugar mixture and whisk until well incorporated.
19Return to the pan and cook over low heat until thick. Add the gelatin and mix.
20Allow to cool.
21Melt and temper the white chocolate to reach a temperature of 115F
22Add 70 gr. of whipped cream, folding gently with a rubber spatula.
23Add the lemon mixture and the remaining whipped cream.
24To assemble, cut the cake into a 9 inch circle.
25Place in the bottom of a 9 inch spring form pan lined with parchment paper, (hazelnuts side up).
26Top with a layer of chocolate-gianduja mousse, let it set in the fridge for about 1 hour.
27Then top with a layer of lemon mousse. Smooth the surface and store in your fridge until set.
28Unmold the cake. Garnish with melted lemon jam.