Cake:

• Preheat the oven to 350°F. Line the bottom of two 9-inch cake pans with parchment paper and grease the sides. Mix cake mix, egg yolks, oil, Jell-o, sour cream, and milk in a large bowl. Set aside.
• With a hand mixer, beat the egg whites on high speed until stiff peaks form, about 4 minutes. Fold the egg whites and strawberries into the cake batter.
• Pour the batter into the prepared pans and bake for 32-36 minutes or until a toothpick inserted in the center comes out clean. Place pan on a wire rack and cool for 10 minutes. Remove the cakes from the pan and cool completely.
• Cut completely cooled and spread a 1-inch layer of whipped topping or whipped cream on one of the cakes. Top with the second layer of cake.
• Spread with additional whipped topping. Refrigerate for at least one hour. Garnish with sliced strawberries.