Add Oreos to a food processor and pulse for 15-20 seconds.
In a medium mixing bowl, cream butter with cream cheese, peppermint extract, white sugar, and red sanding sugar or red food coloring.
Add Oreos to the bowl and fold until well combined and the color is even.
Scoop about 2 tablespoons of the mixture at a time and form little balls. Place onto a parchment paper-lined cookie sheet. Once complete, put the cookie sheet into the freezer for 15 minutes. They will be soft and a bit fiddly to shape but that's fine as you can correct the shape once chilled a bit more.
When the 15 minutes are just about up, start melting the chocolate. Add the wafers or bark to a bowl and microwave in 30-second increments until completely melted.
Use a toothpick to pierce a buttercream ball (or you could use a fork to lift the truffle ball). Dip the ball into the chocolate and swirl to coat completely. Place chocolate dipped truffle back onto the parchment paper and immediately top with sprinkles. The chocolate hardens quickly and the sprinkles will not stick if it does.
Place back into the freezer until 30 minutes before serving.