In a medium saucepan, over medium-high heat, bring the heavy cream and milk to a light simmer.
Remove from heat and add the chocolate chips to the mixture (do not stir and let them set for 5 minutes until melted), then whisk together until combined.
Whisk in the cocoa powder, Oreo crumbs, and salt until incorporated.
Pour the mixture into a heat-safe bowl and place in the refrigerator to chill for at least 6 hours.
Use a small or medium cookie scoop to scoop out the truffle mixture, and roll them between your palms to form a round ball.
Place the balls on a wax paper-lined baking sheet or a silicone mat, and place them in the refrigerator for 2 hours.
Melt the melting wafers in a deep cup or bowl and use a dipping tool or fork to dip the truffles in the chocolate, then place them on a clean sheet of wax paper on a cookie sheet and allow to cool until set.