The 1960s was a time when a desire to experiment was widespread, especially during children's birthday parties. Results were often deliciously naive, like in this showy Easter nest.
Preheat the oven to 180°. Grease a Bundt pan. In a large bowl, beat the eggs with the caster sugar, lemon zest and the grated chocolate, then add the melted butter and mix well. Add the sifted starch and flour, along with the baking powder. Mix well and pour into the pan. Bake for 40 minutes at 180°.
For the cream: mix the rest of the softened butter, the powdered sugar, a small glass of cognac and the cocoa powder: the cream should be fluffy and whipped. Remove cake from the oven and let cool. Then cut in half lengthwise and soak the two halves with a little cognac, then ice with the cream. Put the two halves together and ice the cake with the rest of the cream, using a spatula.
Cover a wire with some satin ribbon and place it on the dessert, like a handle.