INSTRUCTIONS
Position an oven rack in the center of the oven and preheat the oven to 350 degrees. Coat an 8-inch round baking pan with cooking spray, then dust it with flour.
In a large bowl beat 9 ounces of cake mix (about ½ a package), the egg white, water, oil, vanilla and 3 yogurt with an electric mixer until well blended, 2 to 3 minutes.
Pour the cake batter into the prepared pan and bake until a wooden toothpick inserted in the center comes out clean, 25 to 35 minutes. Remove from the oven and cool on a wire rack for 10 minutes. Carefully remove the cake from the pan and place it on the rack to cool completely.
Split the cooled cake horizontally into 2 layers. (I use a thin serrated bread knife.) Place the bottom layer cut side up on a cake plate. Spread ½ the preserves over the bottom layer. Cover with half the whipped cream or whipped topping and half the strawberries.
Top with the remaining layer, cut side down. Coat with the remaining preserves and whipped topping. Arrange the remaining strawberries over the top.