7-Up or Sprite is the secret ingredient that takes this cake to another level, do not allow the soda to go flat pour right from the bottle or can --- this cake bakes out beautiful with no dark over cooked edges --- I recommend to use diet soda regular is too sweet but regular will work fine also ---this also may be baked in two 8-inch round cake pans and it makes the perfect wedding cake!
- 1 (18 ounce) packagemoist deluxe white cake mix (such as Duncan Hines Moist Deluxe Classic White Cake Mix)
- 1⁄3 cup diet lemon-lime soda (such as diet 7-Up or Sprite)
- 1⁄3 cup vegetable oil
- 4 large egg whites
- 1 cup sour cream
- Set oven to 350 degrees F (set oven rack to second-lowest position).
- Mix all ingredients in a bowl on low speed until blended (about 30 seconds).
- Beat at medium speed for 2 minutes more.
- Pour the batter into a greased 13 x 9-inch baking pan (the batter will be quite thick so you will need to spread out with back of a spoon).
- Bake for about 30 minutes or until cake tests done.