Dress a small long pan measuring about 20×30 centimeters with baking paper. Set the oven to 175 degrees.
Break the dark chocolate into pieces. Melt the butter. Remove from the heat, mix in the chocolate and stir until it melts.
Whisk eggs and sugar until fluffy. Whisk the chocolate batter into the egg whisk.
Mix flour, cocoa, baking powder and vanilla powder. Whisk it into the batter.
Pour the batter into the mold. Cut each Snickers into six pieces and gently press down into the batter. Sprinkle with peanuts and press down slightly.
Bake in the center of the oven for about 18 minutes. Let cool.
The cake can be stored in the fridge, but allow to stand for a while at room temperature before serving so that the cake becomes “just sticky”. Cut into squares and powder over cocoa when serving.