Equipment
Ingredients
Graham Cracker Crust
- 150 g graham crackers, crushed into fine crumbs
- 85 g unsalted butter, melted
- 20 g granulated sugar
- 1 g salt
Brownie Batter
- 115 g unsalted butter, cut into chunks
- 115 g bittersweet chocolate, roughly chopped
- 55 g semisweet chocolate, roughly chopped
- 150 g dark brown sugar, packed tightly
- 100 g granulated sugar
- 3 eggs, room temperature
- 10 ml vanilla extract
- 65 g all-purpose flour
- 20 g cocoa powder
- 3 g salt
Topping
- 200 g large marshmallows
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 322 kcal
- Protein
- 3 g
- Carbohydrates
- 45 g
- Fat
- 15 g
- Fiber
- 2 g
- Sugar
- 32 g
- Sodium
- 176 mg
- Saturated Fat
- 10 g
- Trans Fat
- 0 g
- Monounsaturated Fat
- 4 g
- Polyunsaturated Fat
- 1 g
- Cholesterol
- 62 mg
- Potassium
- 111 mg
- Calcium
- 35 mg
- Iron
- 1.3 mg
- Magnesium
- 22 mg
- Phosphorus
- 69 mg
- Zinc
- 0.5 mg
- Vitamin A
- 101 mcg
- Vitamin D
- 0.2 mcg
- Vitamin E
- 0.9 mg
- Vitamin K
- 3 mcg
- Vitamin B6
- 0.1 mg
- Vitamin B12
- 0.1 mcg
- Thiamin
- 0.05 mg
- Riboflavin
- 0.10 mg
- Niacin
- 0.6 mg
- Folate
- 16 mcg
- Water
- 13 g
- Alcohol
- 0 g
- Caffeine
- 6 mg
Sources: USDA FoodData Central
Method
Preheat oven to 175°C (350°F). Line a 20x20 cm baking pan with parchment paper, leaving a slight overhang on the edges for easy removal later.
In a medium mixing bowl, combine the graham cracker crumbs, melted unsalted butter, granulated sugar, and salt. Stir until the mixture resembles wet sand and holds together when squeezed.
Press the crumb mixture firmly and evenly into the bottom of the prepared baking pan. Bake at 175°C (350°F) for 8 minutes until fragrant and slightly set. Set aside to cool slightly.
In a microwave-safe bowl, combine the chunks of unsalted butter, bittersweet chocolate, and semisweet chocolate. Heat in 30-second bursts, stirring vigorously after each interval, until the mixture is completely smooth and glossy.
In a large mixing bowl, whisk together the dark brown sugar, granulated sugar, room temperature eggs, and vanilla extract for about 2 minutes. The mixture should become noticeably paler and slightly thickened.
Pour the warm melted chocolate and butter mixture into the egg mixture. Fold gently with a rubber spatula until fully incorporated into a uniform, dark batter.
Position a sieve over the large mixing bowl and sift the all-purpose flour, cocoa powder, and salt directly into the batter. Use the rubber spatula to fold the dry ingredients gently just until no dry streaks of flour remain.
Pour the brownie batter over the slightly cooled graham cracker crust. Spread it into an even layer with the rubber spatula, ensuring it reaches all the corners.
Bake the brownies at 175°C (350°F) for 25 to 30 minutes. They are ready when the edges look set and slightly cracked, but the center remains soft.
Remove the baking pan from the oven. Carefully arrange the large marshmallows in a tight, single layer over the hot surface of the baked brownies.
Switch the oven setting to broil. Return the pan to the oven and broil for 1 to 2 minutes until the marshmallows are puffed and deeply toasted. Watch constantly, as sugar transitions from toasted to burnt in seconds.
Transfer the pan to a wire rack and allow the brownies to cool completely for at least 1 hour before attempting to lift them out using the parchment overhang. Slice and serve.
Chef's Notes
- Slicing cleanly through a layer of sticky, toasted marshmallows is notoriously difficult. Run a sharp chef knife under hot water, wipe it completely dry with a towel, and make a clean downward slice. Wash and dry the blade between every single cut.
- For the most complex flavor profile, do not substitute all the chocolate for semisweet. The assertive bitterness of the bittersweet chocolate is essential to offset the intense sweetness of the marshmallow topping and graham cracker crust.
- If your oven broiler distributes heat unevenly, use a handheld butane kitchen torch to toast the marshmallows after the brownies have finished baking and have rested on the counter.
- Ensure your eggs are at room temperature before whisking them with the sugar. Room temperature eggs whip more easily, creating a slight aeration that forms the coveted crinkly top on the brownie beneath the marshmallows.
Storage
Refrigerator: 5 days — Cover tightly to prevent the marshmallows from hardening.
Freezer: 1 month — Marshmallow texture may change slightly upon thawing.
Reheating: Microwave a single brownie for 8 to 10 seconds to soften the marshmallow and restore fudginess.
Troubleshooting
Marshmallows caught on fire or burned instantly
Cause: The broiler setting was excessively hot or the pan was placed too close to the upper heating element.
Fix: Carefully scrape off the completely burnt marshmallow tops, arrange a fresh layer, and toast gently using a handheld kitchen torch.
Prevention: Keep the oven rack in the middle position and leave the oven door slightly ajar so you can watch continuously.
Brownies are dry and cakey rather than dense and fudgy
Cause: Overbaking the brownie layer or overmixing the flour into the batter.
Fix: Cannot be fixed once baked, but can be repurposed into a dessert trifle or served warm under a generous scoop of ice cream to mask the dry texture.
Prevention: Remove the brownies from the oven when the center still looks slightly underbaked; they will continue to set as they cool. Mix dry ingredients only until the last streak disappears.
Cultural Context
The concept of a s'more, deriving from the phrase some more, was famously popularized in a 1927 publication by the Girl Scouts of America. This recipe translates the beloved American campfire ritual of roasting marshmallows over an open flame and sandwiching them with chocolate and graham crackers into a stable, portable dessert format perfectly suited for patriotic summer holidays.
