Makes 24 brownies
Adapted from Buttercup Bakes at Home
For the brownies:
For the topping:
Preheat the oven to 350 F. Butter a 9×13-inch pan and set aside.
To make the brownies, combine unsweetened chocolate, butter and 1/3 cup of the semisweet chocolate chips in a microwave safe bowl. Microwave mixture in 30 second intervals until completely melted. Set aside to cool for 5 minutes.
Sift together the flour, baking powder and salt in a medium bowl and set aside.
In the bowl of an electric mixer fitted with the whisk attachment, whisk eggs until light. Add the sugar and vanilla and whisk until completely incorporated. Stir the melted chocolate mixture into the egg mixture and blend well. With the mixer on low, add in the dry ingredients and mix well. Fold in the remaining 1/3 cup semisweet chocolate chips.
Spread the brownie batter evenly into the prepared pan. Bake for 10-15 minutes, or until a toothpick inserted in the center comes out with just a few crumbs.
Remove the brownies from the oven and cover with the marshmallows over them. Place pan back in the oven for 3-5 minutes, until marshmallows puff and melt slightly. Remove from oven and set aside for 5 minutes.
While the marshmallow layer is cooling, combine milk chocolate chips, peanut butter and butter in a microwave safe bowl. Microwave mixture in 30 second intervals until completely melted. Add in graham cracker crumbs and mix well. Allow to cool for 3 minutes.
Spread chocolate graham cracker mixture evenly over the marshmallow layer using a spatula. Chill bars before cutting.