Carefully break 12 to 15 thin Oreo cookies into pieces. Set aside.
Line a 9 x 13 inch microwave safe baking dish with parchment paper.
Place the 16 oz. of white chocolate in the pan.
In one minute increments, heat the chocolate in the microwave, stirring well in between.
The white chocolate should be melted and easily spread to the sides of the pan.
Evenly distribute the oreo pieces on the melted chocolate. Try to avoid crumbs.
Add the M&M's.
Add sprinkles (if desired.)
With a spatula, gently press the cookies, M&M's, and sprinkles into the chocolate.
Refrigerate for 30 minutes, or until hardened.
Remove from pan and break into pieces.