Prepare coffee with a Moka pot or an Espresso Machine and pour it into a deep bowl. Let it cool.

In a large bowl, beat the butter with sugar with an electric mixer until creamy.

Add the egg yolks and continue beating until you get a light and fluffy cream.

In another bowl, whip the egg whites to stiff peaks. The egg whites will be whipped when the mixture does not fall out when the bowl is turned upside down.

Gradually add the egg whites to the buttercream, stirring slowly from bottom to top.

Add liqueur to cooled coffee. You can also skip this step if you wish.

Now assemble the cake by alternating the layers. Take a baking sheet or pan (about cm 25×35) and divide the biscuits into 3 parts and the buttercream into 2 parts.

Dip 1/3 biscuits into the coffee for 1 second and arrange them in one layer on the baking sheet.

Add a layer of 1/2 buttercream, another layer of 1/3 dipped biscuits, and another layer of 1/2 buttercream. Finish with biscuits. The biscuits in each layer must match exactly with the biscuits in the bottom layer.

Cover with aluminum foil and refrigerate for at least 2–3 hours.

Sprinkle with cocoa powder before serving. For a very nice effect, cut the portions following the rectangles (bricks) formed by the last layer of biscuits.