3 1/2 cups coarsely chopped frozen peaches (about 16 ounces)
1/2 cup sugar, preferably superfine (see Note)
1/2 cup nonfat plain yogurt
1 tablespoon lemon juice
Combine peaches and sugar in a food processor; pulse until coarsely chopped. Combine yogurt and lemon juice in a measuring cup; with the machine on, gradually pour the mixture through the feed tube. Process until smooth and creamy, scraping down the sides once or twice. Serve immediately.
Note: Superfine sugar dissolves instantly, preventing a grainy texture in cold desserts and beverages. It is available in the baking section of most supermarkets, but if you can’t find it, simply process regular granulated sugar in a food processor or a clean coffee grinder until ground very fine.