Chocolate Cake with Coffee Buttercream

This is a Nigella Lawson recipe, from her 2017 book, At My Table.

Cake pans dusted with cocoa powder, which makes the baked (unfrosted) cakes darker. Dusting the pans with white flour leaves the baked (unfrosted) cakes with white flakes that can easily be dusted off with a pastry brush.
Mise en place.