Line a half-sheet pan with a dishtowel and place 4 shallow ramekins on it. Set aside. Heat some water in a teapot to use when you pour the eggnog mixture into the ramekins.
Simmer the eggnog. Pour the eggnog into a pan over medium heat and cook, stirring occasionally until the mixture simmers, about 10 minutes.
Beat egg yolks and sugar. While the eggnog is warming, put the egg yolks and sugar into a mixing bowl and beat them until light colored and frothy.
Add mascarpone to egg yolks. Stir the mascarpone cheese into the yolk mixture until blended and smooth.
Combine eggnog and yolks. Whisk 1/4 cup (50 ml) of the heated eggnog mixture into the beaten yolks to temper them, so they do not scramble when cooked. Then, gradually whisk the remaining eggnog into the yolks.
Strain the eggnog. Pour the eggnog mixture through a fine mesh sieve to remove any egg strands.
Add spices. Stir in the nutmeg, cinnamon and cloves.
Pour into ramekins. Pour the mixture into the ramekins, dividing evenly. Set pan in the oven. Then fill the pan ½ full with boiling water.
Cook the crème brûlée for 30 – 45 minutes. The centers should wiggle just slightly when shaken, but not be soupy.
Let cool. Remove the ramekins from the water bath and cool for 30 minutes, then refrigerate for at least 3-4 hours or overnight before serving.
Get out your blowtorch (or fire up the broiler). When ready to serve, sprinkle each serving with 1 teaspoon (5 ml) granulated sugar and caramelize with a kitchen torch or under a pre-heated broiler.