Coat a 9-inch springform pan with cooking spray; set aside. Thaw frozen raspberries, if using, at room temperature for 15 minutes. Drain thawed berries.
In a medium bowl combine the 1 cup flour, 1/2 cup of the sugar, and the baking powder. Add melted butter, 1/4 cup of the egg product, and 1 teaspoon of the vanilla; stir until combined. Spread onto bottom of prepared pan; sprinkle with raspberries.
In another medium bowl combine the yogurt, remaining 1/2 cup sugar, remaining 1/4 cup egg product, the 2 tablespoons flour, the lemon peel, and the remaining 1 teaspoon vanilla. Stir until smooth; pour over berries.
Bake in a 350 degree F oven about 35 minutes or until center appears set when shaken gently. Cool in pan on a wire rack for 15 minutes. Loosen and remove sides of pan; cool completely. Cover and chill for 2 to 24 hours before serving. Makes 12 servings.