Line a cookie sheet with parchment or wax paper. Set aside.

In the top of a double boiler, in a glass bowl over a pan of simmering water, or in the microwave for short (30 second) bursts, melt the chocolate. Stir the chocolate frequently between microwave intervals or while it is on the stove. As soon as the chocolate is melted, remove it from the heat.

*Do not allow any water to get into the chocolate.

Set one Oreo onto a large fork over the bowl of melted chocolate. Use a large spoon to scoop melted chocolate over the top of the cookie to cover it, and scrape away the excess with a knife. Gently push the cookie off of the fork onto a parchment or wax paper lined cookie sheet. Decorate immediately with sprinkles, chopped nuts, or chocolate shavings (if desired).

Allow the chocolate to set completely. In a warm environment, you can allow the chocolate to set in the fridge* for a maximum of 10 minutes or the freezer for a maximum of 4 minutes.

Note: The chocolate on cookies set in the fridge or freezer may crack.

Use a sharp knife to trim away the tails of chocolate. Package or serve as desired.

Store cookies in an airtight container at cool room temperature.