Place the yogurt in a large fine mesh strainer or colander lined with cheesecloth set over a large bowl. Refrigerate and let drain overnight. Discard the whey that has dropped into the bowl or reserve for another use.
In a blender, puree the mangos and 1 cup of the sugar. Taste and adjust sweetness, depending upon the ripeness of the fruit, adding more sugar as needed.
In a large bowl, whisk together the yogurt cheese, pureed mangoes, and vanilla. Refrigerate until well chilled, about 2 hours.
Fold in the whipped cream. Transfer to an airtight container and freeze until ready to use.
In a bowl, toss the raspberries with the liqueur, if desired, and the sugar. Let this macerate for 15 minutes to 1 hour.
To make the parfaits, drizzle a spoonful of the macerated raspberry juice into the bottom of 4 footed parfait glasses. Alternately, place a scoop of the mango frozen mousse and a spoonful of the berries into the glasses, finishing with berries on top. Place in the freezer to get hard, 15 to 30 minutes, or until ready to serve.
To serve, top each parfait with white chocolate shavings.
Yield: 4 servings