Preheat the oven
to 375°F/190°C/gas 5. Butter two madeleine pans
(for 20-24 madeleines).
Sift the flour, cocoa,
baking soda, and salt into a medium bowl. Beat the
eggs, coffee granules, and vanilla in a large bowl
with an electric mixer at high speed until blended.
Beat in the confectioners' sugar and continue
beating until thick. Mix in the dry ingredients
and butter.
Spoon the batter into the prepared
cups, filling each three-quarters full.
Bake for
10-12 minutes, or until springy to the touch. Cool
the madeleines in the pans for 15 minutes.
Transfer to racks and let cool completely. Spread
with the frosting.