Set aside 4 short glasses or ramekins.

1. Separate the eggs. The yolks and the whites of the eggs should be placed in two separate mixing bowls (large bowls). 
2. Add the sugar to the egg yolks and whisk until the mixture becomes pale and slightly foamy, about 5 minutes. Add the mascarpone and vanilla, whisk until mostly incorporated and set aside.
3. Add the pinch of salt to the egg whites and whisk, using electric mixer on medium-high, until stiff peaks form.
4. Fold a quarter of the whisked egg whites into the egg yolk-mascarpone mixture. In three more equal batches, gently fold in the remaining egg whites. Stop mixing once incorporated, be gentle! You’re looking for a fluffy mixture. 
5. Lightly dip the speculoos cookies in the brewed coffee. 
6. Building the tiramisus: At the bottom of each glass, start with a layer of cookies. Then a layer of the mascarpone cream, followed by another layer of cookies, and then mascarpone again. The top layer should be mascarpone cream.
7. Refrigerate the tiramisu for at least 3 hours. Dust with cocoa powder before serving. Enjoy!