1 1/2 cups all purpose flour
2 teaspoons baking powder
1 teaspoon salt
1 cup (2 sticks) unsalted butter
6 ounces unsweetened chocolate, chopped
5 large eggs
1 1/4 cups dark brown sugar
1 cup granulated sugar
2 teaspoons vanilla
1 cup graham cracker, roughly crushed with your hands ( I used chocolate graham crackers)
12 big marshmallows (I added mini marshmallows to the batter as well)\
Preheat oven to 350°F. Butter 9×13-inch baking pan with 2-inch-high sides. Combine first 3 ingredients in small bowl. Stir butter and chocolate in a medium sized bowl over a heavy saucepan of simmering water. Stir chocolate and butter in this double boiler until melted and smooth.
Beat eggs, sugar and vanilla in large bowl to blend. Stir in warm chocolate mixture, then dry ingredients. Fold in graham crackers. Pour batter into prepared pan. Dot with 12 large marshmallows. Bake until toothpick inserted into center comes out with moist crumbs attached, about 30- 40 minutes minutes.
Marshmallows will be browned and puffy but will deflate as the brownies cool. Cool for at least 20 minutes than slice with a sharp knife, cleaning the knife with hot water if it gets too messy and sticky. Serve or wrap individually in wax paper for storing.Marshmallow Frosting:
2 egg whites
1 1/2 cups white sugar
1/3 cup cold water
1 1/2 teaspoons light corn syrup
1 teaspoon vanilla extract
1 cup miniature marshmallows
Put egg whites, sugar, water and syrup in top of double boiler. Beat until mixed well. Place over rapidly boiling water. Beat constantly with electric beater while it cooks for 7 minutes or until it will stand in peaks when beater is raised. Remove from heat.Stir in marshmallows and vanilla. Beat until they melt.