Preheat nothing, as this recipe does not require baking.

Crush 9 of the Oreo cookies to fine crumbs in a food processor; reserve for later use.

Crush the remaining Oreo cookies to fine crumbs and place them in a medium bowl.

Add the cream cheese to the bowl with the crushed Oreo cookies and mix until well blended.

Roll the Oreo and cream cheese mixture into round balls, about 1 inch in diameter.

Melt the chocolate in a double boiler or in the microwave in 30-second increments, stirring between each interval, until smooth and uniform.

Dip each ball one at a time in the melted chocolate using two forks to dip, rotate, and remove each truffle.

Place the truffles on a wax paper covered surface.

Sprinkle the reserved cookie crumbs or sprinkles over the top of the truffles.

Refrigerate the truffles until firm, about 1 hour.

Store leftover truffles, covered, in the refrigerator and serve cold or at room temperature.