Heat the single cream in a small saucepan. Once hot, add the chopped dark chocolate and mix until completely melted. Remove from heat.
In a bowl, mix the two eggs with the hazelnut butter. Then add the cream and chocolate mixture, and mix well.
Add the dry ingredients: flour, almond powder, baking powder, salt, and freshly ground Timut pepper. Mix one last time.
Preheat the oven to 180°C (conventional heat). Line a loaf pan with parchment paper and pour in the batter. Bake for 25 minutes.
At the end of the baking time, let the cake cool completely. Once cooled, unmould it and cut it into slices.
Cut stars in the centre of each slice using a cookie cutter. Keep the trimmings for snacking (freezing possible)!
Prepare the vanilla batter: mix the eggs with the agave syrup and the cream. Add the plain flour, almond powder, baking powder, salt, and scraped vanilla pod. Mix.
Preheat the oven to 180°C (conventional heat). Grease a loaf pan and spread some vanilla batter on the bottom.
Arrange the chocolate stars tightly in rows. Cover with the remaining batter and bake for 30 to 35 minutes, until the cake is golden brown.