Heat oven to 325 degrees F. Boil water for a water bath, easiest to use a tea kettle. Place four 5- ounce ramekins into a baking dish.
Whisk sugar and egg yolks in a medium sized bowl until the color lightens and there is a thickened, creamy texture. Heat Shamrock Farms Half & Half and Irish Whiskey Eggnog in a saucepan on medium heat until bubbles begin to form around the edges. Stir occasionally for about 5 minutes. Do not let boil.
Temper the eggs by slowly adding ½ a cup of the heated half & half-eggnog mixture to the egg and sugar while whisking constantly. Once incorporated, repeat with another ½ cup half & half-eggnog mixture. Add the yolk and half & half-eggnog mixture back into the pot of remaining hot cream, still stirring constantly to not get scrambled eggs.
Pour the custard equally among the 4 ramekins. Pour the heated water into the cake pan until it’s half way up the ramekins, creating a water bath.
Bake in the water bath for 40 minutes or until the centers are set. Cool at room temperature and refrigerate for at least 3 hours.
When ready to serve, evenly cover each custard with 1 tsp granulated sugar and use a kitchen torch or oven broiler to caramelize the tops.