Disappearing Marshmallow Brownies

I thought I had posted this recipe already, as it is one of my most requested ones. Mom used to make these for us growing up and I still love them! I just made them for a bake sale here at work and you know I had to steal a couple for myself. I usually double the recipe, cause they are that good.

Disappearing Marshmallow Brownies (courtesy of Hope's mama)

1/4 cup butter
1/2 cup butterscotch chips
3/4 cup all purpose flour
1/2 tsp baking powder
1/4 tsp salt
1/3 cup brown sugar
1 egg
1 tsp vanilla
1 cup semi-sweet chocolate chips
1 cup mini marshmallows

Preheat oven to 350 degrees. Coat an 8x8 or 9x9 pan with cooking spray.

Stir the butter and butterscotch chips over medium low heat until they are melted. Remove from heat and let cool to room temperature. Stir in the flour, baking powder, salt and brown sugar. Beat the egg and add it and the vanilla. Add the chocolate chips and the marshmallows and gently fold them in (no more than 5 strokes).

Spread the mixture into the pan and cook for 20-25 minutes. The center will still be "jiggly". Let cool and then cut and enjoy.