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–+ servings
Two frosted lunch lady brownies stacked on top of each other with sheet pan of brownies in the background.

Lunch Lady Sheet Pan Brownies

These are the frosted brownies of your school cafeteria dreams, and they are every bit as good as you remember. A half sheet pan full of fudgy brownies topped with a simple chocolate frosting makes for a big batch that is absolutely perfect for feeding a crowd. You can easily get 36 generous squares out of one pan, which means no one goes home empty handed.
Prep Time15 minutes
Cook Time30 minutes
Total Time45 minutes
Servings: 36 Servings
Author: Carlee

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 optional

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 1 cup butter, 1 cup vegetable oil, 3½ cups granulated sugar, 1 cup cocoa powder and 4 teaspoons vanilla extract.
  • Add 8 large eggs one at a time, mixing well after each addition.
  • In a separate bowl, mix together 2½ cups all purpose flour, ¼ teaspoon baking soda and 1 teaspoon salt.
  • Stir flour mixture into butter mixture until uniform. Fold in 2 cups chocolate chips if desired.
  • Spread brownie mixture in prepared pan and bake for 25-30 minutes. Allow to cool.

Chocolate Frosting

  • Stir together ⅔ cup cocoa powder and ¼ cup hot coffee or water. Set aside for a minute or two.
  • Beat ½ cup butter until smooth and fluffy. Add the cocoa mixture and mix until combined.
  • Stir in 5 cups powdered sugar, 1 teaspoon vanilla extract, and ¼ cup milk. Whip until smooth.
  • Spread over cooled brownies.

Nutrition

Serving: 1piece | Calories: 370kcal | Carbohydrates: 52g | Protein: 3g | Fat: 18g | Saturated Fat: 8g | Polyunsaturated Fat: 4g | Monounsaturated Fat: 4g | Trans Fat: 0.4g | Cholesterol: 62mg | Sodium: 151mg | Potassium: 120mg | Fiber: 2g | Sugar: 42g | Vitamin A: 299IU | Calcium: 25mg | Iron: 1mg
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