Oreo Brownies are topped with a layer of homemade Oreo Frosting. These easy homemade fudgy brownies are a delicious flavor variation on a classic brownie recipe.
Table of contents
Black Cocoa Brownies with Oreo Frosting
These oreo brownies with oreo frosting are everything you want in a brownie - rich and fudgy brownies, and a fluffy oreo frosting.
Making homemade brownies is super easy - I switched things up a little and used black cocoa in the brownie recipe, which is what gives oreos their super rich chocolate flavour. These oreo brownies would make a great dessert or anytime snack.
I love brownies for how versatile they are - they can be eaten alone, used as a base for brownie bars like my peanut butter brownie bars and brownie caramel slice, or topped with a frosting like these oreo brownies.
How to make brownies
The Brownie is ever so slightly adapted from Sarah Kieffer’s book, which is one of my absolute favourites to use for base recipes. Sarah makes her brownies in a 9” x 13” (which I sometimes do too, and it makes the most beautiful crackly top and fudgy brownie), but I made this one in a 9” pan to make it a teeny bit thicker, and subbed the cocoa for black cocoa to give it an oreo taste.
I highly suggest making this, but I also highly suggest getting Sarah’s book and making the original - they are some of the best brownies I’ve ever had, and the other recipes in the book are also crazy amazing.
These brownies are a stir together recipe and come together quickly.
- Melt butter and chocolate. This gives you a smooth base to use for your brownies. Remove from the heat and add the cocoa powder. This step helps prevent any cocoa powder lumps.
- Combine dry ingredients. Mix together the flour, baking powder, and salt.
- Combine wet ingredients. It is important that you combine the egg, sugar, vanilla extract and oil well, as you want to avoid over mixing the brownie batter once the flour goes in.
- Mix together brownie batter. The chocolate and butter mixture is incorporated into the eggs and sugar, then add the flour and gently mix.
- Transfer to pan. I used a 9 inch baking pan (23cm) for this recipe, but you can also make brownies in a 9 by 13 inch pan for a thinner brownie - just adjust the baking time.
What is Black Cocoa Powder?
Black Cocoa is cocoa which has been 'ultra dutched' - treated with an alkalising solution which removes the acid from the cocoa, making it super dark and rich in colour and also in taste. This is the same process used for making dutch cocoa, but black cocoa is just processed more heavily. Both dutch cocoa and black cocoa are an unsweetened cocoa powder.
Black cocoa adds an incredible depth of rich chocolate flavor to recipes - it is the cocoa used in Oreos that gives them the slightly bitter, rich taste, and I love using it where I can when I want a deep chocolate hit. You can sub black cocoa wherever dutch-process cocoa powder is called for in a recipe.
Oreo Frosting Recipe
I made an oreo frosting to top my oreo brownies. I used a German buttercream for the base, which is based on a pastry cream. Once the butter was incorporated, I added oreo crumbs.
It is important to not mix the buttercream too much once the oreo crumbs have been added in order for the mixture to not go too gummy.
To make oreo crumbs I separated whole oreos, discarded the filling, and processed the cookie part until it formed fine crumbs.
If you don't want to make a German buttercream, you could add oreo crumbs to a simple vanilla frosting recipe to make an oreo buttercream - a double batch of my vanilla buttercream would work great.
I like to make the pastry cream ahead of time, preferably the night before, but if you are in a pinch, you can spread it in a shallow plate or bowl, then pop it in the freezer to chill, stirring often (greater surface area = faster cooling). If you make the pastry cream before you bake the brownies, it should be cool enough by the time they are cool for you to proceed with making the buttercream.
How to fix a split buttercream
During winter sometimes it is hard to get butter to ‘room’ temperature, which may cause your buttercream to split slightly or not totally come together. If this happens (it looks like there are still chunks of butter in it), you can simply microwave a few tablespoons of the buttercream until melted, and then beat into the mixture. The temperature of the melted buttercream should be enough to warm up the mixture enough for it to come together. Don’t freak out! It happens to me all the time when the weather is cold or your butter isn’t quite warm enough.
Tips for Perfect Brownies
There are a couple of tips and tricks that will help to give you perfect brownies.
- Make sure that you use the right sized pan. I always make my brownies in a metal pan as I find metal pans give the most consistent result. If you want to use a ceramic or glass baking dish, you will need to increase the bake time slightly.
- Line your pan well to make it easy to remove the brownies after they are baked. I like to do this by either greasing the pan or spraying with cooking spray, then adding two layers of parchment paper that extend over the sides of the pan to form a sling. You can clip the parchment down using binder clips to help it stay.
- Make sure your ingredients are at room temperature, especially your eggs. To bring your eggs to room temperature quickly, you can place them in a bowl of warm water for 5-10 minutes.
- Do not over mix your brownies - you do not want to develop gluten, which can make them tough and cakey.
- Ensure that you do not over bake your brownies! It can be hard to tell when they are done, but you are better off with some slightly under baked brownies than over baked.
What is a neutral oil?
Neutral oil refers to the taste of the oil - so something that is neutral flavoured. The best oil to use for brownies is a neutral oil. It provides moisture and gives the brownies an amazing texture, while not taking away from the chocolate flavour. A neutral oil such as vegetable oil, canola oil, extra light olive oil or grapeseed oil would work great here.
How to tell when brownies are baked
This can be a little hard with brownies as you don't want to over bake them and risk getting dry or cakey brownies . The best way to tell if a brownie is baked is to go by sight - it should be set on top and not wobbly when you shake it.
You can also test your brownie with a toothpick, which should come out with a few moist crumbs attached.
FAQ for Oreo Brownies
Yes, these will store well. The brownie base can be made the night before and stored in an airtight container.
Once the oreo brownies are frosted you will need to store them in the fridge in an airtight container. Bring to room temperature if you can before enjoying.
You can use whatever you like here - I prefer something dark such as a bittersweet or semi-sweet chocolate (something around 70% cocoa solids). A milk chocolate I find to be a little sweet for making brownies.
Made this recipe and love it?
If you made this recipe then I would LOVE for you to leave me a review below to let me know how you liked it! Also, please make sure to tag me on Instagram if you make it!
A note on salt and oven temperature
It is important to note the type of salt that is called for in a recipe. I use Diamond Crystal salt throughout my recipes - if you use a different sort of kosher salt or regular table salt you will need to adjust accordingly as some salt is 'saltier' than others. Morton's salt is twice as salty, so you will need half the quantity. Same goes for a regular table salt. I am working to get gram measurements throughout my recipes for salt but still getting there.
All oven temperatures are conventional unless otherwise stated. If you are baking on fan / convection, you will need to adjust the temperature. An oven thermometer is a great investment to ensure that your oven is the correct temperature.
Using the double / triple function in the recipe card
You will notice that there is a '1X' '2X' '3X' button in my recipe card. This can be used for doubling or tripling a recipe. However, please note that this only doubles the ingredient quantities in the ingredients list and NOT in the method. If there are quantities or pan sizes in the method of the recipe (for example weigh out 150g brown butter), you will need to scale this number manually. It will also not change the baking time in the recipe so you will need to adjust this yourself too. It is always a good idea to read through a recipe fully before doubling it just to check this. If you would like to scale this recipe or convert for another pan size, use my calculator!
Tools and equipment
For a list of my go-to tools and equipment, I have a post you can refer to here.
Why is this recipe in grams?
I post my recipes in grams as it is the most accurate way to bake. Cups are not only inaccurate but they vary in volume worldwide. There is no way for me to provide one cup measure that works for everyone. However, posting in weight fixes this issue. If you would like the recipe in cups you are welcome to convert it yourself via google, but please do not ask me to do it for you as I am not comfortable providing a recipe using a method that I have not tested. Baking with a scale is easy, accurate, and also makes cleanup super simple. Here is the scale that I use if you would like a recommendation! Here's to accurate baking!
Recipe for Oreo Brownies
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Oreo Brownies
- Prep Time: 1 hour
- Cook Time: 30 minutes
- Total Time: 3 hours
- Yield: 16 servings 1x
- Category: brownies
- Method: baking
- Cuisine: american
Description
Oreo Brownies are topped with homemade Oreo Frosting. These easy homemade fudgy brownies are a delicious flavor variation on a classic brownie recipe.
Ingredients
Black Cocoa Brownie
- 113g cold unsalted butter
- 225g dark chocolate, coarsely chopped
- 50g Black cocoa, or extra dutched cocoa
- 140g all-purpose flour
- ½ tsp baking powder
- ¾ tsp salt
- 4 large eggs, at room temperature
- 120g neutral oil
- 300g sugar
- 100g brown sugar
- 2 tsp vanilla
Oreo German Buttercream
- 110g sugar
- 12g (1 ½ Tbsp) Corn Starch
- 1 egg
- 1 egg yolk
- ½ tsp salt
- 190g whole milk
- 1 tsp vanilla bean paste
- 340g unsalted butter, at room temperature
- 15 Oreo cookies, cream filling removed, ground finely in food processor or blender
- Extra Oreo cookies for garnish, optional
- Flaky Sea Salt to garnish, optional
Instructions
BLACK COCOA BROWNIE
- Preheat the oven to 350˚f / 180˚c. Grease a 9” square baking tin and line with a parchment paper sling.
- Melt together the butter and chocolate in a medium pan over low heat, stirring well until smooth. Add the cocoa powder and mix well to combine, then set aside to cool.
- Whisk together the flour, baking powder, and salt in a small bowl. In a large bowl, combine the eggs, oil, sugar, brown sugar, and vanilla. Mix until well combined. Add the chocolate mixture and mix until combined. Gently fold in the dry ingredients until just combined.
- Transfer the mixture to the prepared baking tin. Bake for 30 to 35 minutes, until the top of the brownie is set and a skewer inserted comes out with still a few crumbs attached. Remove from the oven and allow to cool completely.
OREO GERMAN BUTTERCREAM
- In a bowl, whisk together the sugar, corn starch, egg, egg yolk and salt. In a medium saucepan, heat the milk and vanilla to just shy of a simmer. Remove from the heat.
- Using one hand to whisk constantly, pour half of the hot milk mixture into the egg mixture. This helps to temper the eggs and stop them from scrambling. Whisk until incorporated, and then pour the whole lot back into the saucepan.
- Heat the milk and egg mixture over medium heat, whisking constantly, until it begins to bubble. It will thicken quickly. Once it has thickened, cook for one minute, then remove from the heat. Pour into a shallow container or bowl of a stand mixer and press some plastic wrap over the surface to avoid a skin from forming. Refrigerate until cold - at least four hours, preferably overnight. If you need to speed this process up, you can place the pastry cream in a bowl, then place the bowl in an ice bath. Stir frequently.
- Fit your mixer with the whisk attachment, and place the pastry cream in the bowl. Whip the mixture on medium until creamy and lump-free. Begin adding the butter, a few cubes at a time, until fully incorporated. It may look curdled at some point but just keep whipping - it will come together! If you are having issues with it coming together, see notes. Add the Oreo crumbs and mix until combined.
ASSEMBLY
- Using an offset spatula, spread the Oreo buttercream over the surface of the brownie, adding swoops as desired. Top with flaky sea salt and extra Oreo pieces. Slice using a sharp knife, wiping the blade between each cut.
- Store leftovers in an airtight container.
Notes
Brownie recipe slightly adapted from The Vanilla Bean Baking Book
During winter sometimes it is hard to get butter to ‘room’ temperature, which may cause your buttercream to split slightly or not totally come together. If this happens (it looks like there are still chunks of butter in it), you can simply microwave a few tablespoons of the buttercream until melted, and then beat into the mixture. The temperature of the melted buttercream should be enough to warm up the mixture enough for it to come together. Don’t freak out! It happens to me all the time when the weather is cold or your butter isn’t quite warm enough.
Keywords: brownies, chocolate, oreo brownies, black cocoa
Comments
These are delicious and German buttercream is the best!
★★★★★
These are delicious and the buttercream is amazing!
★★★★★
This was a huge success and a massive win with the people that ate it! Like all of Erin's recipes it's clear and gives you some great tips and tricks if things don't go your way! I was getting a little nervous about the buttercream but I read the notes and BOOM, my panic was set aside and it all came together with the helpful tip of heating some butter! Thanks Erin! 🥰
★★★★★