Buttermilk brownies are soft, rich, and wonderfully moist, with a warm chocolate-buttermilk frosting that settles into the tender cake-like base. The buttermilk adds a subtle tang that balances the sweetness and deep chocolate flavor, making every bite smooth, tender, and satisfying.
This buttermilk brownies recipe has the feel of an old-fashioned Southern dessert, the kind often found at family gatherings, potlucks, and holiday tables. It is simple to make, uses everyday baking ingredients, and delivers a homemade chocolate dessert that tastes comforting and familiar. The texture is closer to a chocolate sheet cake than a dense fudge brownie, but it slices beautifully into brownie squares and is easy to serve to a crowd.
Why You’ll Love These
These moist buttermilk brownies are made with a boiled chocolate mixture that gives the batter a smooth, tender crumb. Once baked, the warm brownies are topped with a glossy chocolate buttermilk frosting that spreads easily and sets into a soft, sweet finish. If you enjoy Texas-style chocolate sheet cake, this recipe has that same nostalgic flavor in an easy brownie form.
- Soft and tender texture: Buttermilk helps create a moist, cake-like crumb that stays delicious for days.
- Rich chocolate flavor: Cocoa powder is used in both the brownies and the frosting for a classic chocolate dessert.
- Balanced sweetness: The slight tang from the buttermilk keeps the brownies from tasting overly sweet.
- Simple ingredients: Flour, sugar, cocoa, butter, eggs, and buttermilk come together without complicated steps.
- Great for sharing: A 9×13 pan makes enough brownies for parties, potlucks, bake sales, or family desserts.
- Easy warm frosting: The icing is poured over the brownies while they are still warm, creating a smooth and glossy topping.
If you prefer a denser and chewier brownie, choose a fudgy brownie recipe instead. These buttermilk brownies are best for anyone who loves a soft chocolate dessert with a tender, cake-like bite.
Please see the recipe card below for the complete ingredient list, exact measurements, and full instructions.
How to Make Buttermilk Brownies
Step 1 – Preheat the oven to 350ºF. Spray a 9×13 baking pan with non-stick baking spray, preferably one that contains flour, so the brownies release cleanly after baking.
Step 2 – In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking soda, and kosher salt. In a medium saucepan set over medium-high heat, combine the unsalted butter, unsweetened cocoa powder, and water. Bring the mixture just to a boil, stirring constantly. Remove it from the heat and pour it into the dry ingredients. Beat with an electric mixer on medium speed until the batter is combined.
Step 3 – Add the buttermilk, eggs, and vanilla extract. Beat for one minute, just until everything is smooth and evenly mixed. Pour the batter into the prepared baking pan. The batter will be thin, which is normal for this recipe. Bake for 20 to 25 minutes, or until the center is set and a toothpick inserted in the middle comes out clean.
Step 4 – As soon as the brownies come out of the oven, prepare the chocolate buttermilk icing. Place the powdered sugar in a large bowl. In a medium saucepan over medium heat, combine the butter, cocoa powder, and buttermilk. Bring the mixture just to a boil, stirring constantly. Remove it from the heat, pour it into the powdered sugar, add the vanilla extract, and beat until smooth.
Step 5 – Spread the warm chocolate icing evenly over the warm brownies. Place the pan on a wire rack and allow the brownies to cool completely before cutting them into squares.
Tips
- Do not overmix the batter: Mix only until the flour disappears and the batter comes together. Overmixing can make the brownies less tender.
- Sift the powdered sugar if needed: Sifting helps prevent small lumps in the frosting and creates a smoother finish, though it is not always necessary.
- Frost while warm: Pour the chocolate buttermilk frosting over the brownies while they are still warm so it sinks in slightly and sets beautifully.
- Use Dutch-process cocoa for a deeper flavor: If you want a darker chocolate taste, Dutch-process cocoa powder is a good option.
- Cool before slicing: Let the brownies cool completely so the frosting can set and the squares cut neatly.
- Do not worry if the icing mixture separates: The boiled chocolate mixture may look greasy at first, but it will blend smoothly once mixed with the powdered sugar.
Variations
- Add nuts: Stir chopped pecans or walnuts into the batter for crunch and a nutty flavor.
- Make them extra chocolatey: Fold chocolate chips or chocolate chunks into the batter before baking.
- Add warm spice: A small pinch of cinnamon or cayenne can add subtle warmth without changing the basic recipe.
- Try an espresso twist: Add a teaspoon of instant espresso powder to enhance the chocolate flavor.
FAQs
Buttermilk is important because its acidity reacts with the baking soda, helping create a soft, light, and moist crumb. It also adds a gentle tang that balances the richness of the chocolate and gives these buttermilk brownies their signature flavor.
Yes. Add 1 tablespoon of white vinegar to a liquid measuring cup, then add enough milk to make 1 cup total. Skim, 1%, 2%, or whole milk will work. Use 1/2 cup of the mixture for the brownies and 3 tablespoons of the remaining mixture for the frosting.
Yes. Let the brownies cool completely, then stack them with parchment paper between the layers in a freezer-safe container. Freeze for up to 3 months and thaw overnight in the refrigerator.
Store the brownies tightly covered at room temperature for up to 4 days.
More Delicious Dessert Recipes
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Buttermilk Brownies Recipe
Ingredients
Brownies
- 2 cups all-purpose flour
- 2 cups granulated sugar
- 1 teaspoon baking soda
- 1/2 teaspoon kosher salt
- 1 cup unsalted butter
- 1/3 cup unsweetened cocoa powder
- 1 cup water
- 1/2 cup buttermilk
- 2 large eggs
- 1 teaspoon vanilla extract
Chocolate Buttermilk Icing
- 1/4 cup unsalted butter
- 3 tablespoons unsweetened cocoa powder
- 3 tablespoons buttermilk
- 2 1/4 cups powdered sugar
- 1/2 teaspoon vanilla extract
Instructions
Brownies
- Preheat the oven to 350ºF. Spray a 9×13 baking pan with non-stick baking spray that contains flour.
- In a large bowl, whisk together the flour, sugar, baking soda, and kosher salt.
- In a medium saucepan over medium-high heat, combine the butter, cocoa powder, and water. Bring just to a boil, stirring constantly. Remove from the heat and pour the mixture into the dry ingredients. Beat with an electric mixer on medium speed until combined.
- Add the buttermilk, eggs, and vanilla extract. Beat for one minute. Pour the thin batter into the prepared baking pan.
- Bake for 20 to 25 minutes, or until the center is set and a toothpick inserted in the middle comes out clean.
Icing
- When the brownies come out of the oven, make the icing. Place the powdered sugar in a large bowl.
- In a medium saucepan over medium heat, combine the butter, cocoa powder, and buttermilk. Bring just to a boil, stirring constantly. The mixture may separate and look oily, but it will blend smoothly with the powdered sugar.
- Remove the saucepan from the heat. Pour the hot chocolate mixture into the powdered sugar, add the vanilla extract, and beat until smooth.
- Spread the warm chocolate icing evenly over the warm brownies. Place the pan on a wire rack and cool completely before slicing.
Notes
- Don’t overmix: Mix just until the flour disappears for the most tender texture.
- Expect the frosting base to separate: The boiled chocolate mixture may look greasy, but it will come together when beaten with the powdered sugar.
- Frost while warm: Pour the icing over the warm brownies so it seeps in slightly and sets into a smooth topping.
- Storage: Store tightly covered for up to 4 days, or freeze for up to 3 months.
Nutrition
| Carbohydrates: 37 g
| Protein: 2 g
| Fat: 11 g
| Saturated Fat: 6 g
| Sodium: 110 mg
| Sugar: 28 g