Can a bottle of lemon-lime soda make a boxed yellow cake more interesting? This easy sheet cake keeps the eggs and oil from the package directions, then swaps the water for an equal amount of regular 7UP. The method is familiar, but the finished cake can have a tender crumb and a gentle citrus note. It is a simple option when you want a quick dessert without starting from scratch.
Recipe at a glance
- Yield: one 9-by-13-inch cake, about 12 squares
- Prep: about 10 minutes
- Bake: roughly 34–36 minutes, or until the center tests done
- Oven: 350°F (175°C)
Ingredients
- 1 standard 15.25-ounce box yellow cake mix
- 1 cup regular 7UP, freshly opened
- ½ cup vegetable oil
- 3 large eggs
These amounts match a box that normally calls for 1 cup water, ½ cup oil, and 3 eggs. If your cake mix lists different quantities, follow its egg and oil instructions and replace only the specified water with the same volume of 7UP. Use regular soda for the closest result; diet soda can behave differently because it lacks sugar.
How to make a 7UP yellow sheet cake
1. Prepare the pan and oven
Preheat the oven to 350°F (175°C). Grease a 9-by-13-inch metal baking pan thoroughly, including its corners. Put the oven rack in the middle position so the cake can bake evenly. Have the soda measured and ready just before mixing; fresh carbonation is best used promptly.
2. Make the batter
Pour the cake mix into a large bowl. Add the eggs and oil, then pour in the 7UP. Stir with a whisk or beat with a hand mixer on medium speed for about two minutes, following the package guidance. The batter may foam briefly as the soda meets the dry mix. Stop once it is smooth and combined; prolonged beating can make the cake less tender.
3. Bake until the center is set
Spread the batter evenly in the prepared pan and place it on the center rack. Begin checking at the bake time printed on your cake-mix box. In a 9-by-13-inch metal pan, this version may take around 34–36 minutes, but oven and pan differences matter. The top should spring back lightly when touched, and a toothpick inserted in the middle should come out clean or with a few moist crumbs. If the top colors before the center is done, loosely cover it with foil for the final minutes.
4. Cool and serve
Set the pan on a rack and let the cake cool before cutting. The crumb should be soft and evenly baked, with a light lemon-lime note behind the yellow-cake flavor. Serve it plain, dust it with powdered sugar, or add a glaze once completely cool.
Optional lemon glaze
For a brighter finish, whisk 1 cup powdered sugar with 2–3 tablespoons fresh lemon juice until pourable. Drizzle it over the cooled cake. A little finely grated lemon zest adds more citrus aroma. Vanilla or cream cheese frosting also works, though those toppings make the soda flavor less noticeable.
What changes when you use soda?
7UP contributes liquid, sugar, lemon-lime flavor, and carbonation. You may notice a slightly frothy batter and a cake that browns a little more readily than one made with water. The citrus is usually mild after baking, so the dessert still tastes primarily like yellow cake. The exact texture depends on the particular mix, pan, oven, and mixing time; the toothpick test remains the reliable guide.
For a similar swap, another regular lemon-lime soda can be used in the same amount. Other flavors will change the cake more noticeably. Store the cooled cake covered at room temperature for about two days, or refrigerate it if you use a perishable frosting.
