For The Brownie Layer:
For The Chocolate Mousse Layer:
For The Whipped Cream Layer:
Sprinkle a third of the remaining M&M's on top of the brownies, allowing them to settle in the cracks. Add a layer of chocolate mousse, then whipped cream. Repeat, ending with whipped cream on top. Refrigerate overnight and serve.
Chocolate Mousse Layer
Whipped Cream Layer