How To Make Irish Coffee — Irish Coffee Recipe Ingredients: 1-1/2 oz Irish whiskey, 1 tsp brown sugar, 6 oz hot coffee, whipped cream. Directions: Combine whiskey, sugar and coffee in a mug and stir to dissolve. Float cold whipped cream gently on top. Do not mix. As an added treat you can drizzle some Crème de Menthe over the whipped cream.