For the ganache:
Chop the chocolate.
Boil the cream.
Pour over the chopped chocolate, and mix to obtain a smooth mixture.
Incorporate the butter while mixing. At the last moment, add the pepper.
Reserve.
For the macarons:
Mix the icing sugar and almond powder.
Sift to get a very fine result.
Beat the egg whites with the sugar until stiff.
Pour the almond-cocoa powder-sugar mixture over the beaten egg whites in a shower.
Incorporate with a spatula.
Pipe into small macarons on parchment paper with a plain piping tip.
Bake at 450°F for 10 minutes.
Let air dry for at least 30 minutes.
Let cool before loosening.
Fill with dark chocolate ganache.