Whisk the eggs with the pinch of Salt and the Sugar until really foamy - about 10 minutes.
Slowly add the Oil, Milk, and Espresso while mixing.
In a different bowl, mix the flour, baking powder, and cocoa and put it through a sieve.
Slowly add the dry ingredients to the wet ingredients and mix until just combined.
Grease a baking pan (size above) and fill the batter in.
Bake for about 60 minutes - if necessary, cover the cake with aluminum if it gets to dark at the end.
Let the cake cool completely and cut twice so you have three cake layers.
Make the French Buttercream
Over hot water, whisk the eggs with the salt and sugar and keep whisking for 10 minutes.
Pour the mix into a high bowl and whisk with an electric mixer until nice and foamy.
In a different bowl, whisk the butter until fluffy and then slowly add the egg-mix, the espresso, and the cocoa powder.
Fill into a piping bag with a wide, round opening or tip.
The Cream
Whisk the Cream while adding the stabilizer. Optional, add a little sugar.
Whisk in the espresso powder at the end.
Chop the chocolate and fold it into the cream.
Fill into a piping bag with a wide opening, round or tip.
Assembling the Cake
On a plate or pan that is a little larger than your cake, put some espresso and optional some Irish Cream. The bottom should be just covered, don't use too much.
Put the first cake layer in that pan to soak the liquid.
With the dry side down and the soaked side up, place the layer onto a cake plate.
Put a thick rim of French Buttercream around the rim, then use the whipping cream for another round inside and again the Buttercream until the layer is covered with Filling.
Use the second layer and soak as described before, put it on top of the first layer and repeat the previous step.
Put the third layer on top and cover the cake with the remaining cream.
Put into the fridge and let set.
Decorate
Whip some more cream and fill into a piping bag with a star tip.
Use additional cream or use leftover from the filling and mix the buttercream with the whipped cream, then cover the cake with it. Chill it in the fridge.
Heat the 300 g / 1¼ cups cream and pour it over the chocolate. Stir until the chocolate and cream have combined.
Pour the chocolate grenache over the cake and let it drip on the sides.
Set 12 swirls of whipped cream on top of the cake and add a chocolate mocha bean on top.