Name: Buttermilk Brownies
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Cuisine: American
Ingredients: Bars:; 1/2 cup unsalted butter; 1/4 cup unsweetened baking cocoa powder; 1/2 cup vegetable oil; 1 cup water; 2 cups all-purpose flour; 2 cups granulated sugar; 1/2 teaspoon salt; 1/2 cup buttermilk; 2 eggs, beaten; 1 teaspoon baking soda; 1 teaspoon vanilla extract; Frosting:; 1/3 cup buttermilk; 1/4 cup unsweetened cocoa powder; 1/2 cup unsalted butter; 4 cups powdered sugar

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Buttermilk Brownies with Chocolate Frosting are rich, tender, and topped with a luscious layer of creamy frosting that melts into the warm bars for a decadent finish. Made from scratch with simple pantry staples, these classic brownies are perfect for potlucks, family gatherings, or a sweet treat anytime.

Why You’ll Love This Recipe

These brownies are soft, moist, and packed with deep chocolate flavor thanks to the combination of cocoa powder and buttermilk. The silky, pour-over chocolate frosting sets beautifully on top, adding a sweet finish to every bite. This recipe comes together quickly and easily—no special equipment or fancy ingredients required. Whether you’re baking for a crowd or just craving something indulgent, these brownies are a guaranteed hit.

Buttermilk Brownies

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

For the brownies:

unsalted butter
unsweetened baking cocoa powder
vegetable oil
water
all-purpose flour
granulated sugar
salt
buttermilk
eggs
baking soda
vanilla extract

For the frosting:

buttermilk
cocoa
unsalted butter
powdered sugar

Directions

Preheat oven to 350°F (175°C). Grease or spray a 11×15-inch pan with nonstick spray and set aside.
In a large bowl, combine flour, sugar, and salt. Mix well and set aside.
In a medium saucepan over medium-high heat, combine butter, cocoa, vegetable oil, and water. Stir constantly until it comes to a boil.
Remove from heat and immediately pour the hot mixture over the dry ingredients. Stir until just combined.
Add buttermilk, beaten eggs, baking soda, and vanilla extract. Stir until the batter is fully incorporated.
Pour the batter into the prepared pan and bake for 22–27 minutes, or until a toothpick inserted in the center comes out clean.
While the brownies are baking, prepare the frosting. In a medium saucepan, combine buttermilk, cocoa, and butter. Bring to a boil over medium-high heat, stirring constantly.
Remove from heat and stir in powdered sugar, 2 cups at a time, until smooth and thick.
As soon as the brownies come out of the oven, pour the warm frosting evenly over the hot bars.
Let the brownies cool completely in the pan so the frosting can set before slicing and serving.

Servings and timing

This recipe makes approximately 30 brownies.
Prep time: 15 minutes
Cook time: 30 minutes
Total time: 45 minutes

Variations

Nutty version: Add chopped walnuts or pecans to the batter or sprinkle on top of the frosting.
Extra chocolate: Stir chocolate chips into the batter for an extra chocolatey bite.
Frosting twist: Add a teaspoon of espresso powder to the frosting to deepen the chocolate flavor.
Mini pan option: Bake in two 9×9 pans or one 9×13 pan for slightly thicker bars (adjust baking time accordingly).
Gluten-free: Use a 1:1 gluten-free flour blend in place of all-purpose flour.

Storage/Reheating

Store the brownies in an airtight container at room temperature for up to 3 days, or refrigerate for up to 5 days.

To freeze, wrap individual slices in plastic wrap and place in a freezer-safe container. Freeze for up to 2 months. Thaw at room temperature before serving.

FAQs

Can I make these brownies in a different size pan?

Yes, you can use two 9×9 pans or one 9×13 pan, but baking times may need adjustment.

What does buttermilk do in brownies?

Buttermilk adds moisture and a slight tang that balances the sweetness while helping the brownies stay soft and tender.

Can I use Dutch-processed cocoa?

Yes, but it may slightly alter the flavor. Unsweetened natural cocoa powder is recommended for the best result.

Is the frosting supposed to be poured on hot?

Yes, the warm frosting is poured over the freshly baked brownies so it melts slightly into the surface and sets as it cools.

Can I skip the frosting?

You can, but the frosting is a signature part of this recipe’s richness and flavor.

How do I know when the brownies are done?

They’re done when a toothpick inserted into the center comes out clean or with a few moist crumbs, not wet batter.

Can I make these brownies ahead of time?

Yes, they’re great made a day ahead, and the flavors intensify as they rest.

Can I use whole wheat flour?

You can substitute up to half of the all-purpose flour with whole wheat flour, but the texture may be slightly denser.

Do these brownies need to be refrigerated?

Not unless you live in a warm climate. They’re fine at room temperature for a few days but refrigerate if keeping longer.

Can I add mix-ins to the batter?

Yes—chocolate chips, nuts, or even shredded coconut can be folded into the batter for extra flavor and texture.

Conclusion

Buttermilk Brownies with Chocolate Frosting are a tried-and-true classic—moist, chocolatey, and finished with a rich, glossy frosting that makes every bite irresistible. Simple to make and perfect for any occasion, this recipe is a crowd-pleasing favorite you’ll return to again and again. Whether served as a dessert, snack, or sweet gift, these brownies never disappoint.