Preheat oven to 350°F.

Grease and flour a 9”x13” baking pan. Line bottom with parchment paper (see note); set pan aside.

Using a medium saucepan, add the butter, chocolate and 1 cup of chocolate chips. Place over medium-low heat, stirring often, until butter and chocolate have fully melted; set pan aside to cool.

Using a large bowl, mix together the eggs, sugar and vanilla. Stir the egg mixture into the warm chocolate mixture.

Using a medium bowl, sift together the flour, baking powder and salt. Stir the flour mixture into the chocolate mixture.

Stir the remaining ¾ cup of chocolate chips into the batter.

Pour batter into prepared baking pan. Bake at 350°F for 30-35 minutes, or until a toothpick inserted into the brownies comes out mostly clean.

Remove brownies from oven and switch oven to broil (low).

Sprinkle mini-marshmallows evenly on top of brownies and then spread graham cracker pieces on top.

Broil on low for 1-2 minutes, or until marshmallows are golden brown. (Note: Pay close attention at this stage as the marshmallows and graham crackers will burn quickly!)

Remove brownies from oven and sprinkle chocolate pieces on top.

Let cool for at least 30 minutes before slicing.