Whisk the eggs and sugar together until the mixture lightens a little in colour and goes creamy. An electric beater makes this easier but a handheld is fine too.
Place cream, milk, ground nutmeg, cinnamon and cloves in a saucepan over low-medium heat. Stir to combine until the mixture is steaming slightly. Don't let it boil.
Add a large spoonful of the warm milk mixture to your egg mixture, then whisk it quickly to combine. Add another large spoonful and whisk again. Repeat this process until half of the milk mixture has been added to the egg mixture.
Remove the cinnamon sticks from the milk mixture, then pour the egg mixture back into the saucepan on the stove.
Whisk constantly until the mixture reaches about 160F on a cooking thermometer or thickens a little. This will only take a few minutes. Don't worry if it doesn't seem thick enough, it will thicken more as it cools.
Remove from the stove and stir in the vanilla.
Place eggnog in a jug, cover and place in the fridge to cool. If you love cinnamon, add it back into jug before placing in the fridge to steep further.
Pour into your favourite glasses or mugs and stir in 30ml/1oz of Lyre's American Malt to each glass right before serving (optional).
Top with whatever you choose. I love whipped cream and powdered cinnamon.