Layered Raspberry Dessert

Bake and cool cake as directed on package. Cut cake vertically into halves. Freeze half for future use. Tear other half into 3/4 inch pieces. Pour boiling water on Jello. Stir until Jello is dissolved. Add raspberries; break apart with fork. (If desired, remove several berries for garnish.) Refrigerate mixture until thickened but not set, about 15 minutes. Layer half each of cake pieces, gelatin mixture and yogurt in serving bowl. Repeat. Refrigerate, at least 2 hours.