Place four sundae glasses in the freezer for 10 minutes.
Meanwhile, in a bowl, toss the raspberries with the sugar and lemon juice. Let stand for 10 minutes.
Place a scoop of frozen yogurt in each sundae glass. Layer with three quarters of the granola and raspberries. Add a scoop of frozen yogurt. Top with the remaining raspberries and granola. Serve as a dessert for brunch. Kids love it.