This S'mores Brownie Pie takes everything you love about the classic campfire treat and layers it into one spectacular, sliceable dessert. You get a buttery graham cracker crust, a rich fudgy brownie filling, and a crown of toasted golden marshmallows on top. No fire pit or sticky fingers required - just pure, indulgent dessert magic straight from your oven.
Preheat oven to 350°F (175°C). Lightly spray a 9-inch pie plate with nonstick cooking spray.
Combine graham cracker crumbs, sugar, and salt. Stir in melted butter until mixture resembles damp sand. Press firmly into bottom and up sides of prepared pie plate.
Bake crust for 8-10 minutes until golden and fragrant. Cool on wire rack for at least 10 minutes.
Whisk melted butter and sugar until glossy. Add eggs one at a time, then vanilla, beating until slightly lightened.
Stir together flour, cocoa powder, and salt. Fold into wet ingredients until just combined. Fold in chocolate chips if using.
Pour brownie batter into cooled crust and spread evenly. Bake at 350°F for 38-45 minutes until toothpick comes out with moist crumbs.
Cool pie for 15-20 minutes. Spread marshmallows evenly over the top.
Toast marshmallows under broiler for 1-2 minutes watching constantly, or use a kitchen torch for more control. Let rest 10 minutes before slicing.
Notes
Don't overmix: Mix brownie batter only until flour disappears. Overmixing develops gluten and creates a tough, cake-like texture.
Pack crust firmly: Use the bottom of a measuring cup to press crumbs tightly into the pie plate to prevent crumbling when slicing.
Cool before adding marshmallows: Adding marshmallows to a very hot brownie will cause them to sink and melt into the top instead of sitting as a layer.
Watch the broiler: Marshmallows can go from golden to burnt in under a minute. Never walk away during broiling.
Use a hot knife: Dip your knife in hot water and wipe dry before each slice for clean cuts through sticky marshmallows.
Room temperature eggs: Blend more smoothly into the batter and create a more uniform texture.
Make ahead: The crust can be baked up to 2 days ahead. The brownie layer can be baked 1-2 days ahead. Add and toast marshmallows just before serving.
Storage: Store covered at room temperature for 2-3 days or refrigerated for up to 5-6 days. Microwave individual slices for 20-30 seconds to reheat.
Variations: Try swirling in peanut butter, using an Oreo crust, adding espresso powder for mocha flavor, or drizzling with salted caramel.
Box mix shortcut: You can use a standard brownie box mix prepared according to package directions instead of making the batter from scratch.