These brownies are pure cafeteria nostalgia: thick, fudgy squares topped with a shiny chocolate frosting that sticks to your fingers. The shortcut version couldn’t be simpler—everything bakes in one big aluminum sheet pan, and the batter starts with a boxed mix, so you’re not measuring cocoa and flour after a long day.

I first made these for casual Friday night hangouts with neighbors, and now whenever they spot that oversized pan on my counter, they laugh and ask, “Is it brownie night?” They’re practical, crowd-pleasing, and guaranteed to draw people into the kitchen.

Serve them warm with cold milk, hot coffee, or a scoop of vanilla ice cream. For parties, cut smaller bite-size squares so guests can grab one as they pass by. For game nights, set the pan out with paper plates and napkins and let everyone help themselves—it’s the ultimate communal dessert.

5-Ingredient Frosted Sheet Pan Brownies 🍫

Ingredients

Directions

1. Preheat oven to 350°F (175°C). Lightly grease a 13×18-inch aluminum sheet pan.
2. Mix batter: In a large bowl, stir together brownie mix, oil, and eggs until smooth and glossy.
3. Spread & bake: Pour batter into the sheet pan, spreading evenly into corners. Bake 18–22 minutes, until set and a toothpick comes out with moist crumbs.
4. Make frosting glaze: In a microwave-safe bowl, combine frosting and milk. Heat in 15–20 second bursts, stirring until smooth and pourable.
5. Frost brownies: Let brownies cool 10–15 minutes, then pour warm frosting over the top. Spread evenly to the edges.
6. Set & slice: Allow frosting to firm up at room temperature (30–45 minutes) or chill briefly for cleaner cuts. Slice into 24 squares and serve straight from the pan for that nostalgic cafeteria feel.