• Preheat oven to 325F.
• Spray an 8x8 or 9x9 baking pan with cooking spray and line with parchment paper. Let paper extend over two sides for easy removal of brownies.
• Melt bittersweet chocolate and butter together in a microwave safe container. Heat on high for 30 second, stir. Repeat. Let sit for a few minutes and stir again. Chocolate should be smooth and completely melted. If not, heat on 50% power for in 15 second intervals until melted.
• Beat eggs and sugar together in a medium bowl with a fork.
• Mix in salt and vanilla extract. Stir in melted chocolate mixture.
• Stir in the flour just until combined.
• Stir in peanut butter chocolate chips, marshmallows, and semi sweet chocolate chips.
• Pour into prepared pan and smooth top.
• Bake for 25-30 minutes or until center has set.
• Cool brownies completely on a wire rack.

Frosting

• Combine milk chocolate chips and peanut butter in a microwave safe container. I use a glass Pyrex measuring cup.
• Heat on high for 30 second, stir. Repeat. Let sit for a few minutes and stir again. Chocolate should be smooth and completely melted. If not, heat on 50% power for in 15 second intervals until melted.
• Pour over the top of cooled brownies and gently spread.
• Place brownies in the refrigerator until frosting has set up, about 30 minutes. Serve and enjoy!