Make a cup of coffee. Set aside to cool to room temperature.
With the mixer in hand, start whipping the egg whites until you see peaks forming on the surface. While you're whisking away at those whites, gradually sprinkle in about half of the sugar and keep on whisking for another two to three minutes. You'll know it's ready when you've get a nice, sturdy, and glossy mass of egg whites.
Take the remaining half of the sugar and introduce it to the egg yolks. Give it a good whisking until you get a mixture that's looking all light, fluffy, and a beautiful pale yellow.
Mix the mascarpone or cream chese into the yolk mixture using a hand whisk or a spoon, adding it slowly, spoon by spoon. Then gently and slowly stir in the egg whites, again using a spoon or spatula.
Place half Speculoos cookies into the blender. Let them dance in there for just a few seconds – you don't want cookie powder but delightful little cookie chunks.
Put the blended cookies in a separate bowl and mix them with four tablespoons of coffee to get a wet and soft mixture of cookies and coffee.
Quickly blend the other half of Speculoos cookies into cookie chunks.
Mix those coffee-soaked cookies with the ones you've blended. The resultshould be a flawless combination of Speculoos cookies that are part heavenly soaked and part satisfyingly crunchy.
Load the glasses, cups or a pan with a layer of cookie mixture. Then continue with a layer of tiramisu cream.
Continue with another layer of cookies, followed by another layer of cream.
Chill in the refrigerator for at least four hours, preferably overnight.
Sprinkle with cocoa powder, decorate, serve and enjoy :)