bring the milk, molasses, brown sugar, ginger, cinnamon & pepper to a simmer in a small saucepan over medium heat.
cook, stirring, until the sugar has dissolved.
when the mixture comes to a boil, remove from the heat and allow to cool to room temperature.
strain the milk mixture into a small bowl and set aside.
combine the water & the white sugar in a small saucepan and bring to a boil, without stirring< over medium heat.
when the sugar mixture comes to a full boil, continue to boil for 1 minute.
while the sugar boils, beat the egg whites to soft peaks in a large, clean bowl. when the sugar is ready, continue beating the eggs at low speed and very slowly stream in the hot sugar mixture. when all the sugar has been incorporated, turn the mixer to high and beat until the meringue is glossy and has cooled almost down to room temperature, 2-3 minutes.
whisk together the yogurt, vanilla and spiced milk in a large bowl until smooth. fold in the meringue.
pour the yogurt mixture into an ice cream maker and freeze according to the manufacturer's directions.
when the yogurt has finished churning and is still soft, transfer to a large bowl. fold in the candied ginger, if using, until evenly distributed.
transfer to a freezer-safe container and chill in the freezer for 2-3 hours to allow the yogurt to completely set.