Line an 8 x 8″ baking pan with foil or parchment paper, spray the foil with cooking spray, set aside. Place the butter and the chocolate in a heat proof bowl and set over a pan of simmering water, melt until smooth.

Add the biscuits, marshmallows and 3/4’s of the M&M’s to a bowl, When chocolate is melted pour over the cookie mixture and mix well. Pour into prepared pan and smooth the top, sprinkle with remaining M&M’s. Place into the refrigerator for at least 1 hour, then cut and enjoy.