Preheat oven to 350 degrees F. Line a 9x9 inch pan with foil. Spray with non stick spray.
In a large bowl, melt butter in the microwave for 1-2 minutes.
Whisk in sugars, eggs, milk, and vanilla. Then whisk in cocoa powder until smooth.
Add flour gradually, until combined.
Spread batter in prepared pan. Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean. Cool completely.
Heat heavy cream in a medium sauce pan. Add chocolate chips. Stir occasionally until smooth.
Pour ganache over brownies. Smooth with an offset spatula.
Sprinkle with M&Ms. Refrigerate until the ganache has set.
