Simmer frozen blueberries and granulated sugar to make a sauce, then mix room-temperature cream cheese with granulated sugar and unsweetened yogurt. In a separate bowl, add the whipped cream (whipped to soft peaks) and gently mix, then add lemon zest and lemon juice for flavor. Mix some of the blueberry sauce into the mixture to create a marbled pattern, pour into a container, and freeze overnight to set. The result is a refreshing and rich homemade blueberry and cream cheese ice cream.