Place bottom cake layer on a serving plate; spread with half of the filling. (piarecipes.com)
Spread a small amount of buttercream on a cake board, then place bottom cake layer, cut side up, on top. (flourcoveredapron.com)
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. (outside-oslo.com)