Speculoos Mascarpone Mousse:
In the mixer bowl, beat the egg yolks until the mixture has tripled in volume and is clear.
Fold the mixture with the mascarpone, then add the crushed speculoos.

Beat the egg whites until stiff peaks form and fold them into the mascarpone mixture.
Pour the mixture into 6 glasses and refrigerate.

Caramelized Apples:
Peel and core the apples, then cut them into small cubes.
Melt the butter in a pan and cook the apple cubes until they are golden brown.
Sprinkle with sugar and let caramelize, stirring the apples with a wooden spoon to coat them evenly.
Separate the mixture into the glasses, over the speculoos mascarpone mousse, and serve immediately.