Mascarpone Vanilla Ice Cream

In a large saucepan over medium heat, add the milk, heavy cream, and vanilla, stirring often to prevent the bottom from burning.
When the cream mixture is boiling, turn off the heat, cover and allow to sit 15 minutes to enhance the flavor.
Meanwhile, whisk together the egg yolks and sugar until well blended.
In a thin stream, whisk the cream mixture into the egg yolk mixture.
Then pour the egg-cream mixture back into the saucepan.
Heat over medium heat, stirring constantly with a wooden spoon.
At 160 degrees, the mixture will give off a puff of steam.
When the mixture reaches 180 degrees F it will be thickened and creamy, like eggnog.
Or dip a wooden spoon into the mixture.
Run your finger down the back of the spoon.
If the stripe remains clear, the mixture is ready; if the edges blur, the mixture is not quite thick enough yet.
When it is ready, remove it from the heat right away.
Add the mascarpone, and whisk or stir until smooth and well combined.
Meanwhile, in a large bowl, add 1 cup of ice cubes and cover with cold water.
Rest a smaller bowl in the ice water.
Pour the cream mixture through a fine sieve into the smaller bowl in order to remove the vanilla pieces.
Refrigerate until cold, 1 to 1 1/2 hours, then add the crystallized ginger if using, and mix well.
Freeze according to the directions of ice cream maker.
Serve or transfer into a plastic container, cover and freeze until ready to use.