Heat oven to 425 F. Lightly grease 8-inch round cake pan.
In large bowl, combine oats, flour, sugar, orange peel, baking powder, baking soda and salt; mix well. Cut in margarine with two knives until crumbly. Add yogurt; mix with fork just until dry ingredients are moistened.
Turn out onto lightly floured surface. Knead gently 8 to10 times. Pat into prepared pan.
Bake 15 to 20 minutes or until golden brown. Cool 5 minutes in pan. Remove to wire rack; cool slightly.
To serve, cut shortcake into 8 wedges. Top with yogurt and fruit; sprinkle with cinnamon