Gingerbread man cookie (recommended: Pepperidge Farm), for garnish
Pour first 3 ingredients into a cocktail shaker filled with ice. Shake well. Strain into high ball glass or any 8-ounce glass filled with ice. Top with ginger beer. Pour a little dark rum over the back of a spoon and float on top of the ginger beer. Garnish with a gingerbread man cookie.