Prepare the chocolate using whatever method you prefer (melting vs. tempering).
Place an Oreo flat-side down in the chocolate and gently press down to submerge. Maneuver a fork under the cookie and flip it to enrobe the other side.
Remove the cookie from the chocolate and allow any excess to drip off.
If using very fluid chocolate, scrape the bottom of the fork against the edge of the bowl before placing the cookie onto a prepared baking dish. Repeat the process with the remaining cookies.
Immediately add the sprinkles and M&Ms while the chocolate is still wet. Let stand at room temperature for 15 minutes before refrigerating until fully set.
