Chocolate Buttermilk Squares

20 Servings
Prep Time 10 minutes
Cook Time 20 minutes
Total Time 30 minutes

Chocolate Buttermilk Squares are made with buttermilk and cocoa powder in the moist cake and rich frosting. The perfect dessert for a crowd!

These buttermilk bars are made in a big sheet pan, similar to a Chocolate Texas Sheet Cake. Plus, we’ve added buttermilk to this Cake Recipe, which gives the squares a slightly tangy taste and a wonderfully tender texture. Chocolate lovers are sure to go crazy for these Buttermilk Squares!

Chocolate Buttermilk Squares on plate


The key ingredient to these buttermilk bars is, of course, the buttermilk. Buttermilk has a lot of purposes like helping quick bread dough to rise, or making Pancakes extra fluffy. In this Chocolate Buttermilk Bar recipe, it adds a tangy flavor to the cake as well as the frosting. Mixing it into the cake batter also helps to make the recipe extra moist. The finished dessert is unbelievably soft and flavorful!

This delicious treat is sure to become a favorite recipe for when you need to serve a lot of people. The large pan makes them perfect to bring to a potluck, party, or dinner with friends.

Chocolate Buttermilk Squares collage of prep steps

Along with how many servings you get, it is also a super quick recipe. It only takes a few minutes to combine the ingredients, then you only have to bake for 20 minutes, and finish by pouring the chocolate frosting over the top. As long as you give it enough time to cool, you’ll have the perfect dessert that’s easy to transport, and ready to go!


If you don’t want to buy a whole container of buttermilk just to use for one recipe, you can make buttermilk yourself using plain milk and lemon juice or vinegar. 

  • Add 2% milk to a glass measuring cup. Fill it up 1 tablespoon short of the cup mark. 
  • Mix 1 tablespoon lemon juice or vinegar into the glass of milk. 
  • Let the mixture sit for 5-10 minutes at room temperature until it’s slightly thickened with curdled bits.
  • Measure out as much as you need of the buttermilk to use in the recipe. 

Chocolate Buttermilk Squares on baking sheet



  • Prep time: Preheat the oven to 350 degrees, and prep the 15×10 baking pan with nonstick spray and parchment paper. 
  • Chocolate Buttermilk batter: Add the butter, cocoa powder, and water to a saucepan over medium heat. Whisk as the butter melts until the chocolate mixture is well combined. Then remove from heat. In a mixing bowl, combine the sugar, eggs, and vanilla. Whisk until creamy, then stir in the cocoa mixture. Add the flour, baking soda, and salt. Whisk in the dry ingredients until just combined. 
  • Baking time: Pour the batter into the baking dish. Use an offset spatula to make sure it is all spread evenly. Bake for 20 minutes. 
  • Chocolate frosting: Add butter, cocoa powder, buttermilk, powdered sugar, and vanilla extract to a medium saucepan over medium heat. Whisk until the frosting is smooth. Pour over the warm cake and spread it evenly. Let the frosting and cake cool completely before slicing into squares.

Chocolate Buttermilk Squares on plate 


  • Chocolate chips: If you want some extra chocolate in the Chocolate Buttermilk Squares recipe, try mixing some chocolate chips into the batter. Dark chocolate chips, milk chocolate chips, or semisweet chocolate chips would all work well. 
  • Pecans: After adding the frosting, you can sprinkle some chopped pecans over the top of the cake. They’ll add a nice crunch to the moist dessert.
  • Frosting: You can also try adding different kinds of frosting to this recipe depending on your taste. Chocolate Ganache, Buttercream, or Cream Cheese Frosting would all taste good with this simple chocolate cake base.



  • Serve: Kept covered in plastic wrap, Chocolate Buttermilk Squares can keep well at room temperature for up to 4 days.
  • Store: Carefully cover the squares to store them in the fridge for up to 1 week. Leave them out for a half-hour or so to bring them to room temperature before serving.
  • Freeze: Cover the dish in plastic wrap, and then tin foil to keep it in the freezer for up to 3 months. Let it thaw at room temperature before serving.

Chocolate Buttermilk Squares on plate

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Chocolate Buttermilk Squares

Chocolate Buttermilk Squares are made with buttermilk and cocoa powder in the moist cake and rich frosting. The perfect dessert for a crowd!
Yield 20 Servings
Prep Time 10 minutes
Cook Time 20 minutes
Total Time 30 minutes
Course Dessert
Cuisine American
Author Sabrina Snyder


Chocolate Buttermilk Cake:

  • 1 cup unsalted butter
  • 1/4 cup baking cocoa
  • 1 cup water
  • 2 cups sugar
  • 1/2 cup buttermilk
  • 2 large eggs
  • 1 teaspoon vanilla extract
  • 2 cups flour
  • 1 teaspoon baking soda
  • 1/2 teaspoon salt

Poured Chocolate Frosting:

  • 1/2 cup unsalted butter
  • 1/4 cup unsweetened cocoa powder
  • 1/3 cup buttermilk
  • 4 cups powdered sugar
  • 1 teaspoon vanilla extract


  • Preheat oven to 350 degrees and spray a 15x10 baking pan with baking spray and line with parchment paper.
  • To a medium saucepan add butter, cocoa powder, and water on medium heat.
  • Whisk until well mixed.
  • Remove from heat.
  • To a large mixing bowl add sugar, buttermilk, eggs, and vanilla and mix well until creamy.
  • Add in cocoa mixture and whisk well.
  • Add flour, baking soda, and salt, whisking until just combined.
  • Pour batter into baking dish and bake for 20 minutes.
  • To your medium saucepan add butter, cocoa powder, buttermilk, powdered sugar, and vanilla extract.
  • Whisk until smooth.
  • Pour over warm cake and spread evenly.
  • Let cool completely before slicing.


Calories: 358kcal | Carbohydrates: 55g | Protein: 3g | Fat: 15g | Saturated Fat: 9g | Trans Fat: 1g | Cholesterol: 56mg | Sodium: 134mg | Potassium: 72mg | Fiber: 1g | Sugar: 44g | Vitamin A: 469IU | Calcium: 24mg | Iron: 1mg
Keyword: Chocolate Buttermilk Squares

Chocolate Buttermilk Squares collage

About the Author: Sabrina Snyder

Sabrina is a professionally trained Private Chef of over 10 years with ServSafe Manager certification in food safety. She creates all the recipes here on Dinner, then Dessert, fueled in no small part by her love for bacon.

Sabrina Snyder is a professionally trained personal and private chef of over 10 years who is the creator and developer of all the recipes on Dinner, then Dessert.

She is also the author of the cookbook Dinner, then Dessert – Satisfying Meals Using Only 3, 5 or 7 Ingredients, published by Harper Collins.

She started Dinner, then Dessert as a business in her office as a lunch service for her coworkers who admired her lunches before going to culinary school and becoming a full time personal chef and private chef.

As a personal chef Sabrina would cook for families one day a week and cook their entire week of dinners. All grocery shopping, cooking and cleaning was done along with instructions on reheating. As a private chef she cooked for private parties and cooked in family homes in the evenings for families on a nightly basis after working as a personal chef during the day.

Sabrina has been certified as a ServSafe Manager since 2007 and was a longstanding member of the USPCA Personal Chef Association including being on the board of the Washington DC Chapter of Chefs in the US Personal Chef Association when they won Chapter of the year.

As a member of the community of food website creators Sabrina Snyder has spoken at many conferences regarding her experiences as a food writer including the Indulge Food Conference, Everything Food Conference, Haven Food Conference and IACP Annual Food Professionals Conference.

Sabrina lives with her family in sunny California.

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