Crumble the biscuits into fine crumbs, but it is easiest to blend them in a food processor. Then mix them with the rum or liqueur, enough for them to moisten and stick together. In a large oval bowl, lay out foil and spread the biscuit mixture in a thin layer over the entire interior of the bowl.
Separately, beat the cream into snow powder, along with some milk, 2 tablespoons banana-flavored starch, 2 tablespoons rum or liqueur and the box of ice cream. Optionally, add sugar to taste as well. Pour the mixture into the bowl, drop in the chocolate bonbons and cookies randomly and put the ice cream cake for 3-4 hours in a freezer to tighten.
Once well frozen, flip the ice cream cake onto a tray and peel back the foil. You can serve the ice cream cake as is, or covered with 7 oz (200 g) melted and slightly cooled chocolate. Put it back to tighten in the freezer briefly and serve it cut into pieces.
Additionally, you can make a decoration of bonbons, biscuits and whipped cream if desired.