Nutrition per serving may change if servings are adjusted.
¼ cup plus 1 tablespoon sugar, preferably instant-dissolving, divided
¼ cup lemon juice
2 teaspoons freshly grated lemon zest
3 cups vanilla nonfat frozen yogurt
1 cup fresh raspberries
Stir together ¼ cup sugar, lemon juice and lemon zest in a small bowl, until sugar is dissolved.
Process frozen yogurt in a food processor until smooth and slightly softened. Add the sugar-lemon mixture and process until combined. (Alternatively, allow the frozen yogurt to soften slightly and whisk together with the sugar-lemon mixture in a medium bowl until well-combined.) Scoop the frozen yogurt into chilled dessert dishes and return to the freezer to firm up for 30 minutes.
Meanwhile, stir together raspberries and remaining 1 tablespoon sugar in a small bowl; let stand until the berries are juicy, about 15 minutes. Spoon over the frozen yogurt.