For the chai-infused rum: Add the spiced rum (at room temperature) to a jar with the chai tea bags and let steep for 30 minutes. Remove the tea bags and set aside the rum until needed.
For the garam masala simple syrup: Add the sugar, garam masala and 1/2 cup water to a small saucepan and heat on medium until the sugar is dissolved. Set aside and let cool. Stir before using.
For the cocktail: To a shaker filled with ice, add the half-and-half, 1 1/2 ounces of the chai-infused rum, 1 tablespoon of the garam masala simple syrup and a dash (or more, depending on the level of heat you prefer) of cayenne, cinnamon and fresh black pepper. Shake and pour into a cup of ice. Garnish with another quick crack of fresh black pepper and a pinch of cayenne.
Goodbye holiday mimosas. Hello mildly caffeinated exotic spicy sweet sipping beverage.