1/4 cup milk chocolate chips
2 teaspoons butter
3 1/2 fluid ounces Irish whiskey, or more to taste
1/4 teaspoon instant coffee granules
1 teaspoon hot water
1 (14 ounce) can sweetened condensed milk
1 1/2 cups heavy whipping cream
Put chocolate chips and butter in a glass bowl; heat in microwave on high until chips are softened, about 30 seconds. Stir chocolate mixture until smooth, cooking in microwave another 15 seconds to assure chocolate is soft enough, if needed. Add Irish whiskey and stir until smooth.
Dissolve coffee granules in hot water in a small pitcher. Pour the chocolate mixture, sweetened condensed milk, and cream into the pitcher and stir until smooth.
Refrigerate mixture until completely chilled, at least 20 minutes.