Measure out 1 cup of the hot liquid. With the mixer on low speed, add the cup of hot milk/cream to the egg mixture in a slow, steady stream. When thoroughly combined, pour the egg mixture back into the saucepan with the rest of the milk/cream mixture and stir to combine. Cook, stirring constantly, over medium-low heat until the mixture is thick enough to coat the back of a spoon. Transfer to a bowl through a sieve, stir in BaileyÃ¢ÂÂs, cover with a sheet of plastic wrap placed directly on the custard, and chill completely.