Some recipes stick around not because they’re fancy or complicated, but because they’re the kind of thing you can throw together on a whim and still knock everyone’s socks off. That’s exactly what happened with this Diet Coke and cake mix recipe. I first heard about it back in my early twenties from a friend in college one of those always-running-late types who somehow still brought the best treats to the potluck. When she told me it was just Diet Coke and cake mix, I laughed. Thought she was pulling my leg. But then I took a bite. And let me tell you, that cake didn’t last five minutes.
If you’ve been around my kitchen for a bit, you might remember when I shared other nostalgic treats like funnel cake bites, those dreamy cotton candy cloud bites, or even my weekend favorite cinnamon roll pancake recipe. This Diet Coke cake falls right in that same cozy, whimsical category.
I’ve been making it ever since. Over the years, I’ve shared this little gem of a recipe with coworkers at potlucks, neighbors at bake sales, and even that sweet gal at the farmer’s market who was looking for a low-sugar birthday cake for her dad. It’s one of those little kitchen secrets that feels like a magic trick—except it’s real, and it’s darn delicious.

The texture? Oh, it’s super soft, springy, and so moist it practically melts on your tongue. And no, before you even ask—it doesn’t taste like Diet Coke. Not even a little bit. The soda just adds this bubbly lift and rich depth to the chocolate, and if you go with a fudge mix (I always do), it’s like a cheat-code for the best-ever brownie-cake hybrid.
So if you’re craving something sweet but don’t wanna fuss with eggs, oil, and all that cleanup, give this a go. And if you're watching sugar or calories, this one’s got your back too. It's one of those sugar free cake mix and diet soda combos that feels like cheating (in the best way).
It’s a perfect last-minute treat or a sweet fix for a weekday night when you’re already in your pajamas and not about to start cracking eggs. I've made it in my slippers more times than I can count.

Here are some questions folks often ask me…
Can you use Diet Coke with cake mix?
Yep! It’s the magic behind this cake. The carbonation and acidity work together to lift the batter and keep things light without needing eggs or oil.
What to mix with Diet Coke?
Well, besides drinking it with a slice of pizza? 😄 For baking, any boxed cake mix—especially chocolate or spice—is a good partner. And you can top it with Cool Whip, a dusting of cocoa powder, or nothing at all.
Does soda and cake mix work?
Totally! It’s not just a Pinterest myth. The chemical reaction between the soda and dry mix creates a moist, fluffy cake. It’s like food science… but yummy.
Can of Coke in cake mix?
You bet. Regular Coke works too if you’re not doing sugar-free. Just remember: one 12-ounce can is all you need. Don’t overmix!
Diet Coke Chocolate Cake

Diet Coke and Cake Mix Recipe
An ultra-simple, low-sugar chocolate cake made with just a can of Diet Coke, a box of cake mix, and a tub of Cool Whip. Moist, fluffy, and shockingly good.
- Prep Time: 5 minutes
- Cook Time: ~23 minutes
- Total Time: About 28 minutes
- Yield: 16 servings 1x
- Category: Dessert
- Method: Baked
- Cuisine: American
Ingredients
1 (18-ounce) box of chocolate cake mix (I go for fudge with pudding in the mix)
1 (12-ounce) can of Diet Coke
1 (8-ounce) tub of Cool Whip Free or Cool Whip Lite
Instructions
- Preheat your oven to the temperature listed on your cake mix box.
- Grease a 9x13 pan lightly with cooking spray.
- In a large bowl, mix the dry cake mix with the Diet Coke. Use a hand mixer and beat it as directed on the box (usually about 2 minutes at medium speed).
- Pour the batter into the prepared pan.
- Bake for 5 minutes less than the time on the box. So if it says 28 minutes, bake for about 23.
- Check doneness with a fork or toothpick—if it comes out clean, it’s ready!
- Let it cool completely in the pan on a wire rack.
- Once cooled, frost the top with Cool Whip.
- Slice and serve. Store leftovers in the fridge (though honestly, you probably won’t have any).
Notes
- This works with any soda—Diet Dr. Pepper gives it a cherry-chocolate vibe, and orange soda with vanilla
- cake tastes like a creamsicle dream.
- Wanna keep it sugar-free? Use sugar-free cake mix and Cool Whip Free.
- Try it as cupcakes! Just reduce the baking time and keep a close eye.
- Don’t skip the cooling step or your Cool Whip will melt right off. (Been there!)
- Leave a comment and tell me what soda mix-ins you’ve tried!
Nutrition
- Serving Size: 1 slice
- Calories: 116Kcal
- Fat: 2.9g
- Carbohydrates: 23.8g
- Protein: 1.3g
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