Healthy Makeover: Strawberry Shortcakes

Preheat oven to 425 degrees F. Line cookie sheet with parchment paper or foil. In food processor with knife blade attached, pulse oats until coarsely ground. Add flour, baking powder, baking soda, salt, and 3 tablespoons sugar. Pulse until combined. Add margarine; pulse until mixture resembles cornmeal. Add buttermilk and 1 egg white; pulse just until dry ingredients are evenly moistened. With 1/4-cup measuring cup, scoop mixture and drop onto prepared sheet, 2 inches apart. In small bowl, lightly beat remaining egg white. Brush on top of mounds, then sprinkle with 1/2 teaspoon sugar. Bake 16 minutes or until shortcakes are golden brown. Cool completely on sheet on wire rack. Can be kept, tightly wrapped, at room temperature up to overnight. (Refresh before serving in toaster oven or preheated conventional oven at 375 degrees F for 5 minutes.) Meanwhile, in large bowl, combine strawberries, lemon peel, and 1 tablespoon sugar. Let stand. Can be refrigerated, covered, up to overnight. In medium bowl, stir yogurt, sour cream, vanilla, and remaining 3 tablespoons sugar. Can be refrigerated, covered, up to overnight. Split open shortcakes. Divide strawberries and filling among shortcakes.