Preheat oven to 350 degrees F and spray with cooking spray and place parchment paper criss cross in pay of an 8-inch square pan. You can also lightly grease and flour pan.
In a large saucepan, melt 1/2 cup butter.
Remove from heat, and whisk in sugar, vanilla and eggs.
Beat in 1/3 cup cocoa, 1/2 cup flour, salt, and baking powder.
Spread batter into prepared pan.
Bake in preheated oven for 22-27 minutes. D not over bake.
As brownies are cooling, add ½ to 1 cup of mini marshmallows on top of brownies and spread out.
Place marshmallow cream in microwave for 20 seconds and stir with a butter knife and pour on top of the marshmallows and even the marshmallow cream out.
Melt butter in microwave and add chocolate chips and stir to coat the chocolate chips. Place back in microwave for 30 seconds and mix until creamy. Place back in micro for 10-20 seconds if needed.
Pour chocolate mixture on top of marshmallow layer and spread out quickly.
Let brownies cool. Some of the marshmallow might peek out of the chocolate, because of the marshmallows, but it’s ok. :) Gives it character.
Lift brownies out of pan and cut on a board with parchment paper or you can cut in the pan. Keep brownies sealed.
Use half of the ingredients if you want thinner layers of marshmallow and/or chocolate layers. Don't recommend putting these in the fridge. The chocolate turns to chocolate shell and it's not as good if you ask me, but I'm sure if you did put it in the fridge, just pop it in the microwave for a few seconds for a warmed up delicious treat!