Lunch lady brownies are the perfect thing when you need dessert for a crowd. This big batch recipe makes a half sheet pan full of fudgy brownies with a decadent chocolate frosting for an amazing treat.
When you want a giant batch of frosted brownies, these sheet pan brownies are just the thing. This big batch recipe is perfect for parties and potlucks because it makes plenty of fudgy goodness to share.
One of the best parts of the brownies we used to get in the school cafeteria was a nice layer of chocolate frosting, so of course this recipe has that as well. The brownies are good without it, but a little frosting always makes things better!
And both the brownies and the frosting are super simple to make. You can easily cut it onto 36 nice size servings or even more small squares and feed a crowd.
Making Fudgier Brownies
These cakey brownies will remind you of the school cafeteria in the best kind of way. As written, this recipe makes brownies that are on the cakey side.
For fudgier brownies, just leave out the baking soda.
Either way they are absolutely loaded with chocolate and taste amazing. The only difference is the final texture, so it depends if you like them a little bit airy or dense and gooey.
Punching up the Chocolate Flavor
These brownies are rich and chocolaty as written, but adding coffee makes that chocolate taste even better. Just substitute in coffee wherever you see water in the recipe.
I was tempted to do that myself, but figured real lunch ladies might shy away from adding coffee to elementary school desserts. The teachers would likely revolt if they found out the kids were being caffeinated at lunch!
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Adding coffee won’t make the brownies taste like coffee, it will just boost the chocolate flavor. Though you could add coffee extract or concentrated coffee if you did want to go for a stronger coffee mocha flavor (or commit and make coffee and cream brownies).
Storage
Leftover brownies can be stored in an airtight container at room temperature for up to a week. If you find they start drying out, you can add a slice of sandwich bread to the container to help keep them soft longer.
For longer storage, wrap the extra brownies well and freeze for up to 3 months.
How can I make this sheet pan brownie recipe if I don’t have a sheet pan?
This recipe makes a very full 13x18x1″ pan of brownies, so make sure your pan is at least that big. If you don’t have a jelly roll pan that meets those dimensions, you can divide the recipe between two 9×13″ pans.
They won’t take quite as long to bake in the smaller pan, so start checking them after they have baked for about 20 minutes.
More great brownie recipes
We have been on a bit of a brownie roll lately. There are just so many fun ways to make them.
So if you aren’t looking to whip up a giant half sheet pan filled with frosted brownies, don’t despair. We have plenty of other brownie recipes for you.
For a 9×13-inch batch of sticky layered treats, make Mississippi mud brownies. They have marshmallow and chocolate goodness on top of the gooey brownies.
You can also make your own homemade brownie mix and store it for later use. Or load it in a jar and give it as an easy edible gift.
Sheet Pan Brownies
Equipment
Ingredients
Brownies
- 1 cup butter melted
- 1 cup vegetable oil or similar neutral flavored oil
- 3½ cups granulated sugar
- 1 cup cocoa powder
- 4 teaspoons vanilla extract
- 8 large eggs
- 2½ cups all purpose flour
- ¼ teaspoon baking soda
- 1 teaspoon salt
- 2 cups chocolate chips
Frosting
- ⅔ cup cocoa powder
- ¼ cup hot coffee or water
- ½ cup butter softened
- ¼ cup milk
- 1 teaspoon vanilla extract
- 5 cups powdered sugar
Instructions
Sheet Pan Brownies
- Place the oven rack in the middle of your oven and preheat to 350°F.
- Spray a 13x18x1-inch sheet pan with cooking spray and set aside.
- In a large mixing bowl, stir together melted butter, oil, sugar, cocoa powder and vanilla.1 cup butter, 1 cup vegetable oil, 3½ cups granulated sugar, 1 cup cocoa powder, 4 teaspoons vanilla extract
- Add eggs one at a time, mixing well after each addition.8 large eggs
- In a separate bowl, mix together flour, baking soda and salt.2½ cups all purpose flour, ¼ teaspoon baking soda, 1 teaspoon salt
- Stir flour mixture into butter mixture until uniform. Fold in chocolate chips.2 cups chocolate chips
- Spread brownie mixture in prepared pan and bake for 25-30 minutes. Allow to cool.
Chocolate Frosting
- Stir together cocoa powder and hot coffee or water. Set aside for a minute or two.⅔ cup cocoa powder, ¼ cup hot coffee or water
- Beat butter until smooth and fluffy. Add the cocoa mixture and mix until combined.½ cup butter
- Stir in powdered sugar, vanilla, and milk. Whip until smooth.¼ cup milk, 5 cups powdered sugar, 1 teaspoon vanilla extract
- Spread over cooled brownies.
Video
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Not good. The dough spilled over in my oven so huge mess and burned smell. Then, why do you add cocoa powder to hot water? It just made it leave cocoa chunks in the frosting. I didn’t have time to make the frosting again so I’m pretending they are gourmet dark chocolate flakes. I knew I should have stuck with my old recipe, tried and true, and just made a separate frosting. Not a fan of this.
I’m sorry you had trouble with the recipe. The reason you put the cocoa powder in the hot water is to bloom it. It helps to give a richer chocolate taste. I’ve never had it make cocoa chunks, so I am curious about how that happened. You can certainly skip that step if you would like and just add the cocoa powder to the frosting as a dry ingredient.
I noticed it happened when the water wasn’t hot enough. I added a little more hot water to smooth out the cocoa powder then skipped the milk to keep the texture from being runny.
That sounds like a perfect solution. I am glad it worked out for you!
If my pan is a 12 x 18 x 2 do I change the cooking time?
It might take a minute or two longer, but it shouldn’t be a big change. That sounds like the perfect sized pan for this recipe!
Would this be a good recipe to cut into shapes? ? Want to make football brownies for Superbowl.
That’s a fun idea! I think you could cut them into footballs. The scraps would be tasty too, maybe they could be turned into a small trifle or something? Otherwise you could keep them as the cook’s reward!
I went with the fudgy option and opted out of the baking soda. Will definitely be my go to brownie whether I do more fudgy or more cake like. My husband said it was the best brownie he had ever had. It sold like hot cakes at a bake sale. Such a yummy recipe, Thank you for sharing.
I am so happy to hear that, thank you!
Carlee:
If going to freeze just short term, would you frost the brownies before freezing or frost after thawed?
I would wait if you will have to time to frost them later. That way you don’t have to worry about condensation messing with the frosting. However, if you want to get all of the work done ahead of time, you can freeze them frosted. Just defrost them slowly and in a low humidity place to avoid water droplets forming.
Do these freeze well for a week or so?
Yes, brownies freeze well.
How would I adjust this recipe to high altitude? Are you baking in a high altitude location already? Do you have a recommendation?
I don’t have any experience baking at high altitude, but I read that brownies are usually pretty forgiving. The only advice I found was to increase the temperature by 15-25 degrees and shorten the baking time by a few minutes.
Where does the oil go?
With the butter and sugar.
Overflowed in my 13 x 18 pan!!! I would not use this much batter…
Oh no! I am really sorry that happened to you. I know what a pain that is. As you can see from my pics and video, my pan gets full but has never overflowed.
@Laurie, mine over flowed also. I’m wondering if hers had higher sides on the sheet pan.
I am really sorry that happened to you. I usually use a either a Nordicware or OXO 13x18x1″ pan and it is usually full, but I haven’t had it go over. I was planning on making a batch for a party we are hosting in November, but I will put them on my list to make before then and see if we can’t tweak them a bit so they don’t go over.
Hi ladies. I have been working on tweaking the recipe hoping to avoid the overflow issue. The updated recipe has less flour and baking soda, so the results are fudgier so I actually like them better. I have made them a couple of times and haven’t had them run over so hopefully that fixes the problem for you as well. If you make them again, please let me know how it goes. Thank you!
@Laurie, I use Nordic 13x18x2 and it works great.
@Carlee, would you be able to provide the previous flour and baking soda amounts as well? I enjoyed the more cake-like consistency that the brownies had when I used this recipe last summer. Thanks!
Sure thing! I hate changing recipes after they are posted, but I had enough feedback about it going over the edge of the pan that I thought I should in this case. I know what a pain it is to clean the oven after a spill like that. I am glad you liked them so much though! Here is the original recipe:
2 cups butter, melted
4 cups granulated sugar
1 cup cocoa powder
4 teaspoons vanilla extract
8 eggs
3 cups flour
1 teaspoon baking soda
1 teaspoon salt
2 cups chocolate chips
Perfection in brownie form!!!!
Thank you!