1. Preheat your oven to 350 degrees.
2. Into your stand mixer place the melted butter, sugar, cocoa powder and vanilla. Beat on low speed until combined and smooth. Should take about 1 minute.
3. Add the eggs, one at a time, mixing well between each one.
4. In a separate bowl combine the flour and salt. Add it to the batter and mix on medium speed until smooth. Should take about 2 minutes.
5. Add the chocolate chips and stir until combined.
6. Spray a large cookie sheet with cooking spray (mine is 11x17). Scoop 3/4 C of the batter out of the mixing bowl and pour the rest onto the cookie sheet. Spread it out evenly with a knife. The remaining 3/4 C batter can be baked in a loaf pan.(or you can simply discard it). Don't be tempted to add it all to the cookie sheet. It will overflow and you will have a mess on your hands. :)
7. Bake for 25-30 minutes, making sure not to over bake (the loaf pan will bake for less time). The brownies are done when a toothpick inserted into the center comes out clean. Allow them to cool completly.
8. To make the frosting place the melted butter and cocoa in a large mixing bowl. Beat on medium speed until well combined. Add the powdered sugar, milk vanilla and salt and mix until smooth and glossy. Spread evenly over the brownies.
Serve and enjoy!