Chocolate Butter Tater Cake – A Moist, Old-Fashioned Favorite

If you’ve never baked with potatoes, this recipe might surprise you in the best way. Chocolate Butter Tater Cake takes a humble pantry staple and turns it into a rich, velvety dessert that stays tender for days. It has the cozy, nostalgic feel of an old-fashioned bake sale cake, but with a deeper, more satisfying texture.

The potato doesn’t make it taste “potato-y”—it simply makes the crumb lush and moist. If you love chocolate cake that tastes like it came from a family recipe box, this one’s for you.

What Makes This Special

This cake leans on mashed potatoes for moisture and structure, which means you get a soft, dense crumb without it being heavy. The starch from the potato acts like a natural moisture-lock, so the cake stays fresh longer than most chocolate cakes.

It also uses butter for richness and cocoa powder for a deep chocolate flavor that feels classic and comforting. Think of it as the best parts of a butter cake and a chocolate cake, with a little vintage magic.

Ingredients

• 1 cup mashed potatoes, cooled and smooth (plain, no butter or milk added)
• 1/2 cup unsalted butter, softened
• 1/2 cup neutral oil (such as canola or vegetable)
• 1 3/4 cups granulated sugar
• 3 large eggs, at room temperature
• 2 teaspoons vanilla extract
• 2 cups all-purpose flour
• 3/4 cup unsweetened cocoa powder (Dutch-process or natural)
• 1 1/2 teaspoons baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon fine salt
• 1 cup buttermilk, at room temperature
• Optional add-ins: 1/2 cup mini chocolate chips or finely chopped nuts

For the frosting (optional but great):

• 1/2 cup unsalted butter, softened
• 1/4 cup cocoa powder
• 2 cups powdered sugar
• 2–3 tablespoons milk or cream
• 1 teaspoon vanilla extract
• Pinch of salt

Instructions

1. Prep the pan and oven. Heat your oven to 350°F (175°C). Grease and flour a 9×13-inch pan or two 8-inch round cake pans.

   Line the bottoms with parchment for easy release.

2. Make smooth mashed potatoes. If you haven’t already, boil peeled potatoes until tender, then mash until silky with no lumps. Let them cool completely. You need 1 cup, packed but not heaped.
3. Cream the butter, oil, and sugar. In a large bowl, beat the butter, oil, and sugar until light and fluffy, about 3 minutes.

   This traps air and helps the cake rise.

4. Add eggs and vanilla. Beat in the eggs one at a time, scraping the bowl as needed. Stir in the vanilla until combined.
5. Whisk the dry ingredients. In a separate bowl, whisk the flour, cocoa, baking powder, baking soda, and salt until evenly mixed.
6. Combine with buttermilk. Add the dry ingredients to the butter mixture in three parts, alternating with the buttermilk. Start and end with the dry mix.

   Stir just until combined.

7. Fold in the mashed potatoes. Add the cooled mashed potatoes and gently fold until the batter is smooth. If using chocolate chips or nuts, fold them in now.
8. Fill the pan and bake. Spread the batter evenly in the prepared pan(s). Bake for 28–35 minutes for a 9×13 pan or 25–30 minutes for 8-inch rounds.

   The cake is done when a toothpick comes out with a few moist crumbs.

9. Cool completely. Let the cake cool in the pan for 10 minutes, then turn out onto a rack (or leave in the 9×13 pan) and cool completely before frosting.
10. Make the frosting. Beat the butter until creamy. Sift in cocoa and powdered sugar, then add vanilla and a pinch of salt. Add milk a tablespoon at a time until smooth and spreadable.
11. Frost and finish. Spread frosting over the cooled cake.

    Add sprinkles, shaved chocolate, or a light dusting of cocoa if you like.

Keeping It Fresh

Store at room temperature in an airtight container for 2–3 days. The potato helps the cake stay moist without drying out. If your kitchen is warm, refrigerate it, but bring slices to room temperature before serving for the best texture.

To freeze: Wrap unfrosted cake layers tightly in plastic and then foil.

Freeze for up to 2 months. Thaw in the fridge overnight, then frost. You can also freeze individual frosted slices—just wrap well and thaw at room temp.

Health Benefits

• Potatoes add potassium and fiber. While this is still a dessert, using real mashed potatoes gives a small boost of nutrients compared to cakes made only with refined ingredients.
• Cocoa brings antioxidants. Unsweetened cocoa contains flavanols, which have been studied for heart health benefits.
• Better moisture, fewer preservatives. The natural starch and moisture from potatoes help the cake stay soft without additives.
• Portion-friendly. The cake is rich and satisfying, so a smaller slice still feels indulgent.

Common Mistakes to Avoid

• Using hot potatoes. Warm mashed potatoes can melt the butter and lead to a dense, greasy cake.

  Cool them fully before mixing.

• Overmixing the batter. Once you add flour, stir just until combined. Overmixing can make the cake tough.
• Skipping the sifting or whisking step. Cocoa clumps easily. Whisking with the dry ingredients prevents streaks and pockets of powder.
• Guessing on doneness. Start checking a few minutes early.

  Pull the cake when the toothpick has moist crumbs, not wet batter.
• Adding seasoned potatoes. Use plain mashed potatoes—no butter, milk, garlic, or salt from dinner leftovers.

Alternatives

• Dairy-free: Swap butter for a quality dairy-free butter and use plant-based milk with 1 teaspoon vinegar to mimic buttermilk.
• Gluten-free: Use a 1:1 gluten-free baking flour blend and add 1/2 teaspoon xanthan gum if your blend doesn’t include it.
• Sweetener swaps: Use 1 1/2 cups granulated sugar + 1/4 cup brown sugar for a deeper flavor, or try coconut sugar for a subtle caramel note.
• Frosting options: Top with a simple ganache (equal parts warm cream and chopped chocolate) or dust with powdered sugar for a lighter finish.
• Flavor twists: Add 1 teaspoon espresso powder to enhance chocolate, or a pinch of cinnamon and cayenne for a Mexican chocolate vibe.
• Pan variations: Bake in a Bundt pan (50–60 minutes) and glaze; or make cupcakes (18–22 minutes) for easy serving.

FAQ

Do I need a specific type of potato?

Starchy potatoes like Russets work best because they mash smoothly and mix well into the batter. Yukon Golds also work if mashed very smooth.

Can I use instant mashed potatoes?

You can, but make them with water only and mix them thick. The flavor and texture are best with real potatoes, but instant will work in a pinch.

What if I don’t have buttermilk?

Stir 1 tablespoon lemon juice or vinegar into 1 cup milk and let it sit for 5 minutes.

It’s a solid stand-in for buttermilk.

Why add both butter and oil?

Butter gives flavor and oil keeps it moist. Together, they create a tender cake that doesn’t dry out quickly.

Can I reduce the sugar?

Yes, you can cut it by about 1/4 cup without major changes. Reducing more than that will affect texture and moisture.

How do I avoid lumps of potato in the cake?

Mash the potatoes while warm, then cool them.

If needed, push the mash through a fine sieve or use a potato ricer for a silky texture.

Is the cocoa type important?

Both Dutch-process and natural cocoa work here. Dutch-process gives a smoother, darker flavor, while natural cocoa is a bit brighter and more old-school.

Can I make it ahead?

Yes. Bake the cake a day ahead, wrap well, and frost the next day.

The flavor often improves after resting.

Wrapping Up

Chocolate Butter Tater Cake is the kind of dessert that feels familiar from the very first bite. It’s moist, rich, and wonderfully chocolatey, with a texture that stays perfect for days. Whether you frost it tall and pretty or keep it simple in a 9×13, it’s a reliable, crowd-pleasing recipe.

Keep it in your rotation for birthdays, potlucks, or any time you want a cake that never lets you down.