Heat the eggnog on a saucepan just until it starts to bubble around the edges

Remove from heat, stir the freshly grated nutmeg into the eggnog. Cover and allow to infuse.

While infusing, add chocolate to a metal bowl and place over a pot of simmering water. Melt the chocolate slowly. (this can also be done using a microwave).

Remove the bowl of melted chocolate from the heat and wipe any moisture from the bottom. Stir to melt any remaining pieces of chocolate and stir to cool.

Pour one-third of the cooled eggnog mixture onto the melted white chocolate and stir vigorously with a wooden spoon, or a whisk (do not whisk, stir). Repeat with the remaining two-thirds.

Add the bourbon and stir until you have a homogeneous mixture.

If piping, allow to cool at room temperature, stranger to a large piping bag and fill truffle shells. Allow to set and cap shells with remaining tempered chocolate.

If rolling, allow the ganache to cool at room temperature, cover the surface with plastic wrap and refrigerate for four hours, or overnight. Use a measuring spoon or melon baller to scoop small ball shapes. Place the scooped ganache on a sheet pan lined with parchment or silicone mat. Return to the fridge for an hour.

To finish both versions, coat the ganache with a thin layer of tempered chocolate. Embellish with sprinkles and allow to set at room temperature.