Sift the sugar and flour into a medium-sized bowl. Stir in the ground almonds and set aside.
In the bowl of an electric mixer, whisk the egg whites until frothy.
Add the almond mixture and whisk until thouroughly combined.
Whisk in the brown butter and the honey. Add the melted chcolate and whisk to blend.
Spoon the batter into the prepared molds, filling them almost to the top. Refrigerate for about 30 mins. to firm up the batter.
Preheat the oven to 375° F.
Place the tins in the oven and bake until the madeleines are evenly dark brown and springy to the touch, 12-15 mins.
Remove from the oven. Sharply rap the tins against a flat surface to loosen the madeleines. Unmold immediately, using the tip of a sharp knife if necessary, and transfer to a rack to cool.
Serve slightly warm or at room temperature. When completely cooled , the madeleines may be stored for several days in an airtight container.