Buttermilk Brownies
Buttermilk brownies are ultra-moist and topped with a silky chocolate-buttermilk frosting that melts right into the warm cake-like base. Each bite is rich, tender, and perfectly balanced with a hint of tang from the buttermilk.
I grew up with recipes like this that showed up at family gatherings. When I came across a version of these buttermilk brownies years ago, it reminded me of those classic Southern sheet cakes I loved. After a few tweaks, this became one of my go-to recipes. It’s easy, reliable, and has that nostalgic “made from scratch” taste that never goes out of style.
Why You’ll Love These
These buttermilk brownies are rich, ultra-moist, and topped with a warm chocolate-buttermilk frosting that sinks into the soft, cake-like base. They are basically a Texas chocolate-buttermilk sheet cake baked in brownie form.
- Incredibly tender texture thanks to the buttermilk and boiled chocolate mixture.
- Balanced flavor with just the right amount of tang to complement the chocolate.
- Simple pantry ingredients — no fancy steps or equipment needed.
- Feeds a crowd and slices cleanly for parties, potlucks, or holidays.
- Fast and foolproof — the frosting melts right onto the warm brownies for an easy, glossy finish.
- Always a crowd-pleaser with kids and adults alike.
If you prefer a fudgier brownie, try our Fudgy and Chewy Brownies.
Some of our other favorite treat recipes to make are Pumpkin Snickerdoodles, Sweet Potato Bread, Extra Dark Chocolate Fudge, Cranberry Bliss Bars (Starbucks Copycat), and Ultimate Turtle Brownies.
Please see the recipe card below for a full list of ingredients, measurements, and instructions.
How to Make Buttermilk Brownies
Step 1 – Preheat the oven to 350ºF. Spray a 9×13 baking pan with non-stick cooking spray.
Step 2 – In a large bowl, whisk together the all-purpose flour, granulated sugar, baking soda, and kosher salt. In a medium saucepan over medium-high heat, combine the unsalted butter, cocoa powder, and water. Bring just to a boil, stirring constantly. Remove from the heat and pour it into the dry ingredients. With an electric mixer on medium speed, beat it until combined.
Step 3 – Add the buttermilk, eggs, and vanilla extract, and beat for one minute. Pour the brownie batter into the prepared baking pan. The batter will be thin. Bake for 20-25 minutes. The center should be fully set, and a toothpick may come out clean.
Step 4 – 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 to a boil, stirring constantly. Remove from the heat, pour into the powdered sugar, add the vanilla, and beat until smooth.
Step 5 – Spread warm chocolate icing over the brownies evenly. Place the pan on a wire rack and cool completely.
Tips
- Don’t overmix—mix just until the flour disappears for tender brownies.
- Shiny Frosting: Sift your powdered sugar before mixing the icing. It prevents tiny lumps and gives the frosting that ultra-smooth shine. (I don’t find this step necessary.)
- Pour the warm frosting over the brownies while they’re still warm so it seeps in slightly and sets perfectly. The brownies only need to cool for a few minutes while you prepare the frosting.
- If you prefer a deeper chocolate flavor, use Dutch-process cocoa powder.
- Let the brownies cool completely before cutting into squares.
- Do note that the boiled chocolate frosting mixture will separate and look greasy. Don’t worry, it will work into the powdered sugar just fine.
Variations
- Add nuts: Stir in chopped pecans or walnuts for extra crunch and flavor.
- Extra chocolatey: Fold in chocolate chips or chunks into the batter before baking.
- Spiced version: Add a pinch of cinnamon or cayenne for a warm, subtle kick.
- Espresso twist: Add a teaspoon of instant espresso powder to enhance the chocolate flavor.
FAQs
Buttermilk brings two big benefits to this recipe. First, its acidity reacts with the baking soda to create a lighter, softer crumb—exactly what gives these brownies their signature ultra-moist, cake-like texture. Second, it adds a gentle tang that cuts through the richness of the chocolate, giving the brownies a deeper, more balanced flavor.
Yes. Add 1 tablespoon of white vinegar to a liquid measuring cup. Add enough milk (skim, 1%, 2% or whole milk will work) to make 1 cup of buttermilk. You will use 1/2 cup of the buttermilk mixture for the cake and 3 tablespoons of the remaining for the frosting.
Yes, these classic buttermilk brownies freeze beautifully! Stack separated by parchment paper in a freezer-safe container and freeze for up to 3 months. Thaw in the refrigerator overnight.
Store covered tightly at room temperature for up to 4 days.
More Delicious Dessert Recipes
Buttermilk Brownies Recipe
Ingredients
Brownies
- 2 cups All-purpose flour
- 2 cups Granulated sugar
- 1 tsp Baking soda
- 1/2 tsp Kosher salt
- 1 cup Unsalted butter
- 1/3 cup Unsweetened cocoa powder
- 1 cup Water
- 1/2 cup Buttermilk
- 2 large Eggs
- 1 tsp Vanilla extract
Chocolate Buttermilk Icing
- 1/4 cup Unsalted butter
- 3 tbsp Unsweetened cocoa
- 3 tbsp Buttermilk
- 2 1/4 cups Powdered sugar
- 1/2 tsp 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 all-purpose flour, granulated sugar, baking soda, and kosher salt.2 cups All-purpose flour, 2 cups Granulated sugar, 1 tsp Baking soda, 1/2 tsp Kosher salt
- In a medium saucepan over medium-high heat, combine the unsalted butter, cocoa powder, and water. Bring just to a boil, stirring constantly. Remove from the heat and pour it into the dry ingredients. With an electric mixer on medium speed, beat it until combined.1 cup Unsalted butter, 1/3 cup Unsweetened cocoa powder, 1 cup Water
- Add the buttermilk, eggs, and vanilla beat for one minute. Pour into the prepared baking pan. Bake for 20-25 minutes, until a toothpick inserted in the center comes out clean.1/2 cup Buttermilk, 2 large Eggs, 1 tsp Vanilla extract
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. (It will separate and look oily. Don't worry, it will still mix in well with the powdered sugar.) Remove from the heat, pour into the powdered sugar, add the vanilla, and beat until smooth.1/4 cup Unsalted butter, 3 tbsp Unsweetened cocoa, 3 tbsp Buttermilk, 2 1/4 cups Powdered sugar, 1/2 tsp Vanilla extract
- Spread warm chocolate icing over the brownies evenly. Place the pan on a wire rack and cool completely before slicing.
Notes
- Don’t overmix—mix just until the flour disappears for tender brownies.
- Do note that the boiled chocolate frosting mixture will separate and look greasy. Don’t worry, it will work into the powdered sugar just fine.
- Pour the warm frosting over the brownies while they’re still warm so it seeps in and sets perfectly.
- Store covered tightly for up to 4 days or freeze for up to 3 months.