While the brownies start to cool, make the frosting.
Make the frosting by first creaming together the butter and cream cheese until smooth.
Scrape the sides of the bowl and add in the cocoa powder. Add a tsp or two of milk to help bring the mixture together.
Mix on the lowest setting, so we avoid adding extra air to the frosting.
Next, add in the powdered sugar, again, adding a little bit of milk, as needed, to bring the mixture together while mixing on the lowest setting.
Add in the vanilla and mix until combined. The frosting should be thick, creamy and dark in color.
Scoop dollops of the frosting onto the top of the brownies. The heat from the brownies will slightly melt the frosting making it easier to spread.
Spread the frosting onto the brownies to cover the center of the brownies.
Return the brownies to the warm (but off) oven for 3-5 minutes to melt the frosting onto the brownies (this will help get that silky smooth appearance on top of the frosting)
Immediately sprinkle the candy coated chocolate chips on top of the frosting.
Allow the brownies to cool completely in the pan before cutting.
Note: I actually like to freeze my brownies for about 30 minutes before cutting to make it easier to get the brownies out of the pan and easier to get clean cuts. Store at room temp or in the fridge in an air tight container.