
Crust:
6 tablespoons unsalted butter, melted
1 1/2 cups crushed graham cracker crumbs
2 tablespoons sugar
Pinch fine salt
Brownie:
8 tablespoons (1 stick) unsalted butter
4 ounces unsweetened chocolate, chopped
1 cup packed light brown sugar
3/4 cup white sugar
1 1/2 teaspoons pure vanilla extract
1/2 teaspoon fine salt
4 large cold eggs
1 cup all-purpose flour
Topping:
4 cups large marshmallows-- I used mini's and only coated half of the batch.
Position a rack in the lower third of the oven and heat oven to 325. Line an 8 by-8-inch square baking pan with foil so it hangs over the edges by about 1 inch.
For the crust... lightly butter the foil with some of the melted butter. Stir the rest of the butter together with the crumbs, sugar, and salt in a medium bowl. Press the crumb mixture evenly over the bottom of the pan. Bake until golden brown, about 20 minutes.
Meanwhile, make the brownie. Put the butter and chocolate in a medium microwave safe bowl. Melt in the microwave for about a minute. Stir and microwave again until completely melted, about 2 minutes more.
Add the eggs and beat vigorously to make a thick and glossy batter. Add the flour and stir until just incorporated. Pour batter into the prepared pan. Bake until the top is crispy and a toothpick inserted into the middle comes out mostly clean, with a few crumbs, about 40 minutes.
Remove from the oven and carefully position a rack about 6 inches from the broiler and preheat on low. Layer marshmallows across the top and toast under the broiler until golden, about 2 minutes.
What happens if you don't keep an eye on it? Flames. And your big brother running over with a fire extinguisher. Alarms going off. Everyone crowding over the oven. AHH!!!! Scrape off and try again.. though I advise just keeping an eye on it.... slick.
Cool on a rack, gently removing the brownies from the pan using the aluminum flaps. Carefully separate any marshmallow from the foil and fold away.