Cheesecake Ice Cream With Strawberry Sauce

In a food processor, combine yogurt, sour cream, cream cheese, 2 tablespoons sugar, vanilla and zest of 1 lemon; process until smooth, 1 minute. Freeze in an airtight container until solid, 6 hours. In a small saucepan, bring to a boil strawberries, remaining 2 tablespoons sugar, 2 tablespoons water, juice and 1 teaspoon zest; reduce heat and simmer until strawberries soften, 5 minutes. Remove from heat and let cool. In a food processor, process frozen-yogurt mixture and milk until smooth and thick, 1 to 2 minutes. (If ice cream starts to melt, transfer to a bowl and freeze for 20 minutes.) Divide ice cream among 6 bowls. Top each with strawberry sauce, graham cracker crumbs and chocolate curls.