I had a little bit of trouble with the marshmallow layer squishing out to the side when I added the peanut butter layer which may have been because of the difference between kosher marshmallows and standard marshmallows. Next time I will let the marshmallows cool a bit more before adding the top layer and see if that helps. It turns out, though, that we actually liked the edge pieces with the extra marshmallow the best, so I think next time I might add some more marshmallows.

The original recipe says to cut a 9 x 13 pan into 24 bars, but I made a half recipe and cut it into 16 bars and I thought they were plenty big because they are quite rich.

Marshmallow Peanut Butter Crunch Brownies (adapted from Culinary Concoctions by Peabody via Brown Eyed Baker)
Ingredients

Brownie Base
4 ounces unsweetened chocolate
2/3 cup margarine
1 1/4 cups semisweet chocolate chips, divided
1 1/3 cup all purpose flour
1 teaspoon baking powder
1/2 teaspoon salt
4 eggs,  room temperature
2 cups granulated sugar
2 teaspoons vanilla extract

For the Toping
1 bag (10 1/2 oz) minature marshmallows
1 1/2 cups chocolate chips
1 cup smooth peanut butter (don’t use natural peanut butter)
1 Tablespoons margarine
1 1/2 cups Rice Krispies cereal

Preheat the oven to 350. Grease a 9 x 13 inch pan or line it with a sling of parchment paper extending 2 inches over each side.

For the brownies melt the unsweetened chocolate, margarine and 3/4 cup of the chocolate chips in a medium saucepan over medium heat. Stir occasionally while it is melting. Once melted set the pan aside and cool for 5 minutes.

Sift the flour, baking powder and salt together in a medium bowl and set aside. In a large bowl whisk the eggs thoroughly then whisk in the sugar and vanilla. Whisk until well combined. Stir the melted ingredients into the egg mixture and mix well. Stir in the dry ingredients, then fold in the remaining 1/2 cup of chocolate chips.

Pour the batter into the prepared pan, smoothing the surface with a spatula. Bake for 25 to 30 minutes, or until a cake tester inserted into the corner of the pan comes out with moist crumbs. Remove the brownies from the oven an immediately sprinkle the marshmallows over them. Return the pan to the oven for 3 more minutes.

Meanwhile place the remaining chocolate chips, peanut butter and tablespoon of margarine in a medium saucepan. Melt over low heat, stirring constantly, until completely melted. Remove from the heat, add the Rice Krispies and mix well. Allow to cool for 3 minutes.

Spread the mixture over the marshmallow layer. Let the bars cool then refrigerate until chilled before cutting.