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Okay, confession time: the first moment I ever tasted old-fashioned Southern Coca Cola Cake, I was barefoot in my friend Charlene’s steamy, bustling kitchen, kids running wild through the screen door, and the sun blasting down like it does in July. I’d heard whispers about this cake—how it’s got soda in it, which sounded kinda wild to me—but let me tell you, all those rumors were true. Moist beyond belief, fudgy, topped in what can only be described as a sheet of glossy, crackly chocolate frosting. We practically polished off the entire pan before anyone realized the kids had also drained the sweet tea pitcher. Every bite was pure nostalgia, wrapped up in chocolate…and a little magic thanks to one cold bottle of Coca-Cola. I never thought I’d be the kind of gal who craves a cake with soda as the star, but here we are. And listen: if you’re not really a “baker,” this cake has your back. It’s easy, it’s forgiving, and it’s the very definition of homey joy in a 9×13 pan.
If you’ve never tried a true Southern Coca Cola Cake, promise me you’ll give it a shot. It’s one of those classic Southern desserts that just makes sense: the rich, cocoa-laced cake with that hint of cola sweetness, the marshmallow pockets (just trust me), the fudgy icing poured hot and thick over everything. It’s right up there on my “make it for every celebration” list, alongside banana pudding, lemon bars, and a good old-fashioned pecan pie. And if you bring this to a potluck? Prepare for folks to hover around until you share the recipe, or “just a little corner” for their plate.
Why You’ll Love This Recipe
- Unbeatable Moistness: The combo of soda and buttermilk gives you that dream-come-true soft, almost pudding-cake texture. No dry crumbs allowed!
- Deep Chocolate Flavor: Both the cake and the warm fudge frosting are loaded with cocoa. This one’s for the chocoholics, for real.
- Simple, Unfussy Prep: You don’t need fancy gear, and you definitely don’t have to be a pro. Some bowls, a whisk, a saucepan—done!
- Family-Friendly Crowds: It’s birthday cake material, holiday-worthy, or just a “because it’s Tuesday” treat—this cake disappears FAST whenever you serve it.
- Impressively Accessible: If you’re nervous about homemade cakes, relax! The steps are easy, it’s super forgiving, and honestly, it tastes amazing no matter what.
Key Ingredients
Coca-Cola: The real stuff, please. It adds a little sweetness, a hint of caramel, and keeps everything lusciously moist. (Don’t panic if you only have a generic cola—use what’s handy. But classic Coke just hits different!)
All-Purpose Flour: Nothing fancy or cake flour here—just your standard all-purpose makes the crumb tender.
Buttermilk: This is what makes the cake taste so old-school and soft. If you forgot to grab some, it’s okay! Just add 1½ teaspoons lemon juice or vinegar to ½ cup milk. Stir and let it hang out 5 minutes; boom, buttermilk!
Unsweetened Cocoa Powder: Any kind you have will work—Dutch-processed, natural. Just double-check it’s not hot chocolate mix (been there, learned the hard way).
Mini Marshmallows: These are the surprise-and-delight heroes—the secret source of those gooey, melty pockets. If you only have the big ones, chop ‘em small.
Butter: You’ll want this for both the cake and the fudge frosting. Unsalted is nice, but use what’s in the fridge—just cut the pinch of salt if you’re using salted butter.
Confectioners’ Sugar: For that old-fashioned fudge frosting, nothing else will do! If it’s a little lumpy, sift first (or just power through—it melts anyway).
Pecans (Optional): Classic and totally Southern, but if someone’s not a nut fan, leave them off or swap for walnuts. Totally skip for a nut-free treat.
Want the exact amounts? Pop down to the bottom for the recipe card!
Instructions
Step 1: Preheat and Prepare
Set your oven to 350°F. Grease up a 9×13 baking pan—get those corners good! This cake’s a little clingy if you don’t (foil with a bit of nonstick spray works great, too).
Step 2: Combine Dry Ingredients
In your biggest bowl, whisk together 2 cups all-purpose flour, 2 cups granulated sugar, 1 teaspoon baking soda, and ½ teaspoon salt. No need for sifting theatrics—just whisk until it looks nice and uniform.
Step 3: Make the Cocoa Mixture
In a medium saucepan, melt 1 cup butter (yep, 2 sticks) over medium heat. Stir in 3 tablespoons unsweetened cocoa and 1 cup Coca-Cola. Whisk as it comes to a gentle boil—you want it hot and bubbling, not scorched. Don’t wander off!
Step 4: Bring it Together
Pour that hot, steamy chocolate-cola mixture right into your flour mix. (The smell here? Out of control.) Stir or beat until combined—a few lumps are no big deal.
Step 5: Add the Buttermilk Mixture
In a small bowl or measuring cup, gently beat ½ cup buttermilk, 2 large eggs, and 1 teaspoon vanilla together. Add this into your chocolate batter, mixing just until smooth and glossy. It’ll seem slightly thin—don’t panic!
Step 6: Fold in Marshmallows
Add 1½ cups mini marshmallows and gently fold them in. It’ll look crowded, but most will melt away and leave sweet hidden bites (trust me, it’s my favorite part).
Step 7: Bake
Spread that yummy batter in your prepared pan, leveling it out. Bake for 30 to 35 minutes, or until a tester in the center comes out with a few sticky (not raw) crumbs. Start checking around 28 minutes if your oven runs hot. Don’t overbake—this cake loves to stay soft and fudgy.
Step 8: Make the Frosting
While your cake’s in the oven, get your saucepan back out. Melt ½ cup butter (1 stick) with 3 tablespoons cocoa powder and 6 tablespoons Coca-Cola over medium-low heat until bubbling gently. Pull off heat.
Step 9: Finish the Frosting
Whisk in 4 cups confectioners’ sugar and 1 teaspoon vanilla extract. If you’re crazy for pecans (raises hand!), add in 1 cup chopped pecans right now. Stir until smooth, fudge-thick, and glossy.
Step 10: Pour and Frost
The moment the cake comes out (literally, as soon as you set it down), pour your warm frosting over the hot cake. It’ll spread in a lava-creek across the top. Use an offset spatula or the back of a spoon to coax it toward the edges while everything’s steamy and soft. This is what gives that crackly, fudge-shop top.
Step 11: Cool—If You Can Wait!
Let the cake cool in the pan so the frosting can set up and get that signature sheet-cake ‘crust.’ If you sneak a warm square, I promise I won’t tell—the gooey marshmallow bits and melty frosting are absolute heaven with a scoop of ice cream. Otherwise, let it cool, slice, and enjoy the (guaranteed) happy faces.
Serving Suggestions
Good news: this cake is an all-star all on its own, straight from the pan with a fork! But if you want next-level, top with a creamy scoop of vanilla ice cream (especially while it’s still ever-so-slightly warm), a handful of berries, or a swirl of whipped cream. It’s also perfect with a mug of coffee or icy-cold milk for a true Southern treat. For birthdays or special days, I’ve even scattered rainbow sprinkles over the warm frosting—makes it feel all the more celebratory.
Storage and Meal Prep Tips
If somehow you end up with leftovers (hats off to your willpower!), just cover the pan with foil or plastic and stash in the fridge up to 5 days. The frosting sets up a bit, but let your slice come to room temp for that silky, soft texture again. For make-ahead magic, you can bake the cake the day before and save the frosting til closer to serving—that way it stays extra glossy and fresh. Need to freeze? Absolutely. Slice, wrap individually in plastic plus a layer of foil, and freeze for up to 3 months. Just thaw at room temp and enjoy.
Variations
Want to riff on tradition? Try a “Cherry Coke” version: fold in chopped maraschino cherries with the marshmallows. Skip the nuts for a classic kid-approved treat, or throw in some chocolate chips for a true double-chocolate moment. Feeling festive? Bake it in cupcake tins—just cut the time to about 18–20 minutes for bite-size fun! If you’re watching sugar, you can even go with diet cola and swap in a sugar substitute for the frosting—the cake still turns out dreamy-perfect.
Conclusion
This Southern Coca Cola Cake is exactly the kind of cozy comfort food that makes memories at family tables and potlucks (and yeah, maybe midnight snack time, too). There’s just something so heartwarming about a “secret ingredient” cake that’s not fussy or fancy, but always, always delicious. If you give it a go—whether you stick classic or add your own twist—I’d truly love to hear how it turns out! Got questions, family stories, or secret tips of your own? Pop them in the comments below. Happy baking, friends, and don’t forget to sneak a bite for yourself while it’s still warm!
Southern Coca Cola Cake
Ingredients
- 2 cups all-purpose flour
- 2 cups granulated sugar
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1 cup unsalted butter melted
- 1/4 cup unsweetened cocoa powder
- 1 cup Coca-Cola
- 1/2 cup buttermilk
- 2 large eggs
- 1 teaspoon vanilla extract
- 1 1/2 cups mini marshmallows
- 1/2 cup unsalted butter for frosting
- 1/4 cup unsweetened cocoa powder for frosting
- 1/2 cup Coca-Cola for frosting
- 4 cups confectioners' sugar
- 1 teaspoon vanilla extract for frosting
- 1 cup chopped pecans optional
Instructions
- Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking pan to prevent sticking.
- In a large bowl, whisk together flour, sugar, baking soda, and salt.
- In a saucepan, melt butter and stir in cocoa powder and Coca-Cola. Bring to a boil, then pour over dry ingredients and mix well.
- Whisk together buttermilk, eggs, and vanilla, then add to the batter. Mix until smooth.
- Fold in mini marshmallows, ensuring they are evenly distributed.
- Pour the batter into the prepared pan and bake for 30-35 minutes, or until a toothpick comes out clean.
- Melt butter in a saucepan, stir in cocoa powder and Coca-Cola, and bring to a boil. Remove from heat and whisk in confectioners' sugar and vanilla until smooth. Add pecans, if using.
- Pour the warm frosting over the hot cake and spread evenly.
- Let the cake cool completely in the pan before serving.
