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Brownie Sheet Cake

This Brownie Sheet Cake recipe is so good. It’s a mix between a brownie and chocolate sheet cake. Yum!

How about a little sweet temptation? Let me tell you how I came up with this Brownie Sheet Cake recipe.

A couple of years ago my youngest child had a math tournament and his school is hosted it. Parents were asked to bring some goodies for a concession sale. I thought that brownies should be a hit.

In looking through a lot of recipes, though, I realized that most recipes only make a 9×9 or an 8×8 pan. I wanted something bigger.

I combined some elements of a few recipes, tweaked them a little, and bam! Brownie Sheet Cake!


I started off by making a simple chocolate syrup. Just sugar, cocoa, water, vanilla, and a little salt.

boiling chocolate

I make the syrup first because it has to come to a boil and then cool. It will thicken some during the cooling period.

Prepared Pan

While the syrup was cooling, I got to work on other aspects of the brownies, like preparing my 9×13 pan. I lined it with aluminum foil and sprayed it with non-stick spray.

I then got all of my other ingredients together. (Above is flour, baking powder, salt, and espresso powder.)

Typically eggs are added one at a time. I like to crack all of mine into a little glass bowl. I then try to pour them in, one at a time.

The recipe has a mixture of cocoa powder, butter, and oil. This is quite bitter since there is no sugar. But that is okay since there are two cups of sugar in the brownie batter.

Luscious batter – still not ready

This is how it looks before the icing is added.

The icing is a simple chocolate glaze made with chocolate chips, butter, and a little corn syrup.

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Brownie Sheet Cake
4.6 from 42 votes

Brownie Sheet Cake

Brownie Sheet Cake - this dessert recipe is so good. It's a mix between a brownie and chocolate sheet cake. Yum!
Course Desserts
Cuisine American
Keyword brownie, cake, chocolate
Prep Time 15 minutes
Cook Time 40 minutes
Total Time 55 minutes
Servings 16 slices
Calories 492 kcal
Author Lynda


Chocolate Syrup

  • ¼ cup unsweetened cocoa powder
  • ½ cup water
  • 1 cup sugar
  • 1 tsp vanilla
  • ¼ tsp salt

Brownie Batter

  • cups all-purpose flour
  • 1 tsp baking powder
  • 1 tsp salt
  • 2 Tbsp espresso powder
  • 10 Tbsp butter
  • ¾ cup baking cocoa
  • ¼ cup vegetable oil
  • 2 cups sugar
  • 4 large eggs
  • 2 tsp vanilla extract
  • two-thirds cup chocolate chips
  • Chocolate Syrup

Chocolate Icing

  • cups chocolate chips
  • 3 Tbsp corn syrup
  • 1 stick butter


  1. To make the syrup: in a medium or large saucepan, whisk the cocoa powder and sugar until well blended. Add water and whisk over medium-high until it starts to boil and becomes a little frothy. Continue boiling for approximately 3 minutes. Reduce heat and allow to simmer for 2 more minutes. Remove from the heat and add salt. Let cool.
  2. Preheat oven to 350 degrees. Line bottom of 13x9 pan with aluminum foil and spray with non-stick cooking spray.
  3. Combine flour, baking powder, salt, and espresso powder and set aside.
  4. Microwave butter until melted in a medium size glass bowl. Add cocoa and oil and whisk until smooth.
  5. Transfer cocoa mixture to a bowl of an electric mixer. Stir in sugar. Add eggs, one at a time, mixing well after each addition. Add vanilla. Gradually add flour mixture. Pour in chocolate syrup and chocolate chips.
  6. Pour batter into prepared 13x9 pan and bake for 25-30 minutes or until done. Let cool before icing.
  7. To make the icing: Melt chocolate chips and butter together in a microwave-safe bowl in 30 second intervals on high, stirring well after each segment. (It took me a total of one minute + an additional 10 seconds.) Add corn syrup and stir until smooth. Let sit for 5 minutes before pouring over brownies.

Nutrition Facts
Brownie Sheet Cake
Amount Per Serving (1 slice)
Calories 492 Calories from Fat 216
% Daily Value*
Fat 24g37%
Saturated Fat 13g81%
Trans Fat 1g
Polyunsaturated Fat 10g
Cholesterol 81mg27%
Sodium 340mg15%
Carbohydrates 68g23%
Fiber 3g13%
Sugar 53g59%
Protein 5g10%
* Percent Daily Values are based on a 2000 calorie diet.

Like chocolate? Be sure to check out these other delicious chocolatey desserts:

  • Nutella Bread (aka Chocolate Bread) – Luscious Nutella enrobed in a homemade sweet dough – it’s great for breakfast, snack, and dessert!
  • Mini Chocolate Bundt Cakes – These cute little cakes are great for when you crave chocolate cake and you know that you won’t stop with one slice.  Here you can eat the entire (MINI) cake.
  • Easy Salted Caramel Hot Chocolate – This how-to-recipe shows you how to upgrade chocolate milk from ordinary to extraordinary.  

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Recipe Rating

Jeanne B

Monday 20th of July 2020

I made these and they were excellent! I did make two changes though. I don’t drink coffee, so I used onyx powder instead, it’s a very dark cocoa powder, like in Oreo cookies. Also, I was in a hurry so I substituted a layer of Nutella for the icing on top, which turned out delicious, of course, and softened the dark intensity of the brownies in a good way. Everyone gobbled these bad brownie boys up!


Monday 20th of July 2020

Thanks, Jeanne, for stopping by and leaving your comment. It made me happy to hear that they disappeared!


Wednesday 1st of July 2020

Made this recipe, a little over the top with all the sugar oil and butter and the taste wasn’t as good as I was hoping for.


Thursday 2nd of July 2020

Thanks for stopping by and leaving a comment. I hate that they were not what you were hoping for. Honestly, at this stage in my life, I probably would find them too sweet and too rich.


Tuesday 14th of April 2020

Thank you for this recipe! I made these this week ( we added pecans to the icing) and it’s been hands down the best brownies I’ve ever made. Thanks!


Wednesday 15th of April 2020

Your comment makes my heart happy! Thank you so much for sharing. I am so delighted you like the recipe. <3


Friday 3rd of January 2020

Looks amazing. Can’t wait to try them. How much instant coffee instead of expresso? Thanks


Saturday 4th of January 2020

I would double the amount.

Ethel Anderson

Tuesday 4th of June 2019

Would like to bake in a larger sheet cake pan would this work


Wednesday 5th of June 2019

I am not sure. If you were to do that, you would have to adjust the baking time and/or temperature.