To make
the bottom cake layer, cream butter and sugar together until light and fluffy, then start adding the egg yolks, one at a time, until well mixed.
Frost the cake (I frosted
the bottom cake layer first, refrigerated for ~ 20 minutes, topped the bottom layer with the top layer, frosted and then refrigerated for ~ 20 minutes).
I spread this mixture over
the bottom cake layer before putting on the top layer.
To protect the exposed rim of the cake plate from crumbs and frosting smudges as you work, begin by cutting wide strips of parchment paper and placing them under the edges of
the bottom cake layer, overlapping and covering the exposed rim of the cake plate.
To assemble the cake, drizzle a little bit of the kirsch from the soaked cherries onto
the bottom cake layer.