|Preheat oven to 350 degrees F. Grease a jelly-roll pan.|
Mix butter, sugar, flour, nuts, soda and oatmeal together.
Add chocolate chips.
Reserve 1 1/2 cups of oatmeal mixture. Pat remaining oatmeal mixture into prepared pan.
Make brownie mix according to directions on the box. Spread over oatmeal mixture.
Add M&Ms to reserved oatmeal mix and crumble on top.
Bake for 20-25 minutes.