Heat oven to 350 degrees F.
Line a 8" or 9" square pan with aluminum foil and spray with nonstick cooking spray
In Medium bowl, mix brownie batter, oil, water and eggs as called for on box.
Pour 3/4 of batter into pan.
With an electric mixer, beat filling ingredients (starting with pumpkin and cream cheese first) then when smooth add the other ingredients.
Add the filling mix on top of the brownie layer.
Add the remaining brownie mixture and with a knife swirl the two together.
Then add 1/2 a bag of M&Ms on top.
Bake for 45 minutes or until done.
Cool completely in refrigerator.
Take foil out of pan and cut into 16 pieces.