This is actually the second type of s'mores brownies that I've made. In the other version, the graham crackers served as a bottom crust for the brownies, which has marshmallows mixed in. These, on the other hand, are a brownie base topped with chocolate, marshmallows, and graham cracker pieces.
I saw this recipe on the blog Cooking During Stolen Moments. I followed the recipe exactly, as shown below:
1 cup sugar
1/2 cup butter or margarine (I used margarine)
1 1/2 cups chocolate chips
1 1/2 cups flour
1 t. vanilla
1/4 t. baking soda
1 1/2 cups broken graham crackers (I just crumbled up about 5-6 sheets)
2 T. butter, melted
2 cups mini marshmallows (I didn't measure, just used enough to fill the pan)
1 Hershey bar, broken into pieces
1. Heat butter and sugar in a medium saucepan over low heat until melted. Remove from heat and stir in chocolate chips. Let the mixture cool to room temperature.
2. Whisk the eggs in a separate small bowl. Add a little bit of chocolate to the egg mixture to temper the eggs. Pour the eggs into the chocolate and stir to combine.
3. Add flour, baking soda, and vanilla and mix well.
4. Pour batter into a greased 9 x 13 pan.
5. Melt the butter in a small bowl and mix the graham cracker chunks in with the butter. Sprinkle over the brownie batter. Top with the marshmallows and chocolate pieces.
6. Bake in a 350 degree oven for 18-22 minutes (mine took 22 minutes)