Toast the nuts lightly and chop them finely. Crumble the Biscoff. Melt the butter. Mix the nuts, Biscoff, sugar and cinnamon together. Add the oil and melted butter. Do this quickly so that everything is well mixed.
Put this mixture into a loose-bottomed baking tin and press firmly. Bake the base in the oven for 10 minutes and leave to cool.
Whip the cream with the vanilla sugar and icing sugar. Crumble the meringues and fold into the cream using a spatula.
Put the cream into the baking tin and place in the freezer for at least 4 hours.
In the meantime, melt the milk chocolate in a bain-marie and pour over the ice cream cake just before serving.