Dip glass rims in ginger liqueur and crushed gingersnaps. Store glasses in freezer up to 2 days.
Stir together 2 Tbsp. ginger liqueur, vanilla-citrus liqueur, coffee-flavored rum, honey, and whipping cream in a cocktail shaker. Add ice cubes; cover with lid, and shake vigorously until thoroughly chilled (about 30 seconds). Strain into a chilled martini glass. Garnish, if desired.
Note: We tested with Brinley Gold Coffee Rum, Tuaca Vanilla Citrus Liqueur, and Domaine de Canton ginger liqueur.