Lunch lady brownies are the perfect thing when you need dessert for a crowd. This recipe makes an half pan of fudgy brownies with a decadent chocolate frosting for an amazing treat.

When you want a giant batch of frosted chocolate goodness, 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. 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!
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.
Storing Leftover Brownies
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.
Should brownies be on the top or bottom rack?
Brownies should be baked on the middle rack of your oven. That is where they will get the most even heat and will be least likely to burn due to being too close to a heating element.
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 recipes for you.

If that coffee and brownie combination caught your interest, check out coffee and cream brownies. It is a much smaller batch, but the layers make them absolutely stunning.
For a slightly larger batch of sticky layered treats, make Mississippi mud brownies. They have marshmallow and chocolate goodness on top of the gooey brownies.
Or 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.

Rhubarb brownies combine rich fudgy chocolate and brown butter batter with bits of fresh rhubarb. It may sounds like a strange combination, but trust me it works!
Layered monster brownies are the perfect combination of Graham cracker crust, rich chocolaty brownies and peanut butter for an extra special treat.
Love this recipe? Give it a ⭐⭐⭐⭐⭐ review in the recipe card below!
Sheet Pan Brownies

Make a giant sheet pan filled with frosted lunch lady brownies for a chocolaty treat big enough to feed a crowd. They are easy to make the chocolate icing takes them to the next level of delicious.
Ingredients
Brownies
- 1 cup butter, melted
- 1 cup vegetable oil (or similar neutral flavored oil)
- 3 1/2 cups granulated sugar
- 1 cup cocoa powder
- 4 teaspoons vanilla extract
- 8 eggs
- 2 1/2 cups all purpose flour
- 1/4 teaspoon baking soda
- 1 teaspoon salt
- 2 cups chocolate chips
Frosting
- 2/3 cup cocoa powder
- 1/4 cup hot coffee or water
- 1/2 cup soft butter
- 1/4 cup milk
- 1 teaspoon vanilla extract
- 5 cups powdered sugar
Instructions
- Preheat oven to 350°F and spray a 13x18x1-inch sheet pan with cooking spray.
- In a large mixing bowl, stir together melted butter, oil, sugar, cocoa powder and vanilla. Add eggs one at a time, mixing well after each addition.
- In a separate bowl, mix together flour, baking soda and salt.
- Stir flour mixture into butter mixture until uniform. Fold in chocolate chips.
- Spread brownie mixture in prepared pan and bake for 25-30 minutes. Allow to cool.
- To make frosting, stir together cocoa powder and hot coffee or water. Set aside for a minute or two.
- Beat butter until smooth and fluffy. Add the cocoa mixture and mix until combined.
- Stir in powdered sugar and milk. Whip until smooth.
- Spread over cooled brownies.
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Nutrition Information:
Yield:
36Serving Size:
1Amount Per Serving: Calories: 368Total Fat: 18gSaturated Fat: 7gTrans Fat: 0gUnsaturated Fat: 9gCholesterol: 62mgSodium: 147mgCarbohydrates: 50gFiber: 2gSugar: 40gProtein: 4g
All nutritional information is estimated and will depend on the exact ingredients you use.

Mandy Dimick
Friday 17th of February 2023
How would I adjust this recipe to high altitude? Are you baking in a high altitude location already? Do you have a recommendation?
Carlee
Saturday 18th of February 2023
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.
Valerie
Sunday 16th of October 2022
Where does the oil go?
Carlee
Sunday 16th of October 2022
With the butter and sugar.
Laurie
Thursday 28th of July 2022
Overflowed in my 13 x 18 pan!!! I would not use this much batter...
Char
Saturday 25th of March 2023
@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!
Nicola
Friday 17th of March 2023
@Laurie, I use Nordic 13x18x2 and it works great.
Carlee
Sunday 9th of October 2022
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!
Bethany
Monday 26th of September 2022
@Laurie, mine over flowed also. I'm wondering if hers had higher sides on the sheet pan.
Carlee
Friday 29th of July 2022
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.
Andrea Nine
Friday 26th of November 2021
Perfection in brownie form!!!!
Carlee
Saturday 27th of November 2021
Thank you!