Line a baking sheet with parchment paper or a nonstick silicone mat; set aside.
Pulse Oreos in a food processor into fine crumbs and reserve 2 tablespoons of crumbs for topping.
Add the softened cream cheese to the crumbs and pulse until well combined into a sticky dough.
Use a 1 TBS cookie scoop or tablespoon to portion the mixture and roll into balls; place the balls on the prepared baking sheet so they are not touching.
Freeze the Oreo balls for at least 30 minutes to firm before dipping; meanwhile line a second baking sheet with parchment paper or a nonstick mat.
Melt the almond bark or candy melts according to package directions until smooth, then whisk in the shortening until the chocolate is glossy; reheat briefly if it thickens while dipping.
Remove only a few truffles from the freezer at a time so they stay firm; dip the bottom of one ball in the chocolate, balance it on the end of a butter knife or fork, spoon chocolate over until fully covered, let excess run off, then use a toothpick to gently slide the truffle onto the parchment paper.
If not drizzling, immediately sprinkle the tops with reserved crumbs, crushed candy canes, or other toppings while the coating is wet; if you plan to drizzle, let the coating set first, then drizzle and add toppings.
To drizzle, once the truffles are set (about 10 minutes), melt additional chocolate and drizzle over the truffles using a fork or by transferring cooled chocolate to a plastic bag and snipping a corner.
Place the truffles in the refrigerator for at least 30 minutes before serving. If not serving immediately, cover once set or store in a tightly sealed container with parchment between rows.