Melt butter and chocolate in sauce pan. Remove from heat add salt and sugar. Mix in eggs, mascarpone cheese, and flour a little at a time stirring constantly, not to cook the eggs. Mix in baking chips, saving a few for the top.
Spray cooking spray in 9×12 pan spread mixture. Bake in 350° oven for 15 minutes or until toothpick comes out clean. Do not over bake.
Mix together the first 3 ingredients, then add the powdered sugar. Add the milk a little at a time until creamy and the thickness you desire. Mix the coloring in and your ready to frost your brownies.
Sprinkle top with remaining chips.