Preheat your oven to 375°F (190°C).
Melt the butter and dark chocolate together in a bowl.
In a separate bowl, whisk eggs and sugar until pale and fluffy.
Fold in the melted chocolate mixture into the egg mixture.
Sift together flour, baking powder, and salt in a separate bowl.
Gradually fold the dry ingredients into the chocolate batter.
Spoon the batter into madeleine molds, filling them halfway.
Bake for 10-12 minutes until edges are golden and centers are just set.
Let the madeleines cool in the pan for a few minutes before transferring to a wire rack.
Serve warm with a dusting of powdered sugar on top.
