Take two plates. On one plate, spread melted chocolate; on another, scatter crushed biscuits and pearl sugar.
Dip the rim of a cooled glass into the melted chocolate, then into the biscuits and sugar. Place the glass in the refrigerator to cool.
In a cocktail shaker, combine Baileys Irish Cream, Ketel One Vodka, orange peel, and mint.
Shake the ingredients together until fully blended.
Fill the glass halfway with the contents.
Pour the double cream carefully over the top of the drink using the back of a spoon.
Using a wooden skewer, toast a large marshmallow over a flame.