In a large bowl combine melted butter, sugar, cocoa powder, eggs, and vanilla and mix until smooth. Add flour and salt and mix until incorporated. Spread batter evenly in prepared pan. Bake for 25-30 minutes until an inserted toothpick in the center comes out clean (a few loose crumbs are okay but no wet batter).
Spread marshmallows in an even layer on top of the brownie layer. Return to oven and bake another 5-7 minutes until marshmallows are fluffy and beginning to lightly brown. Allow to cool while you prepare the frosting.
In a microwave-safe glass bowl combine chocolate chips and heavy cream and microwave on half power for 2 minutes at a time, stirring after each, until smooth. Stir in butter and vanilla til smooth. Pour mixture over marshmallows. Chill at least 2-3 hours or until completely cooled before cutting into bars and serving.
Updated on April 18, 2021Originally Posted on April 29, 2016