Layout a large piece of parchment or wax paper on a flat surface. Have the oreos (or other sandwich cookies) already to go.
Pour approximately 15 oz. of white chocolate melting wafers into a microwave safe bowl. Reserve about 1/4 of the wafers for the top layer.
Heat the white chocolate in the microwave for 30 seconds at a time, stirring the chocolate well in between each round. Once the chocolate is fully melted, remove from the microwave
Dip the oreos into the melted chocolate. Using a fork, gently flip the cookie to fully coat the other side. Once the cookie is fully coated, use the fork to lift and gently shake off any excess chocolate back into the bowl. Place the chocolate covered cookie onto the parchment or wax paper.Allow the cookies to fully dry before dipping them into the marbled white chocolate.
Once the dipped cookies are fully dry. Prepare the white chocolate marbled topping.
Heat the remaining white chocolate melting wafer in the microwave for 20 seconds at a time, stirring the chocolate well in between each round. Once the chocolate is fully melted, remove from the microwave.
Using an oil based food coloring, drop a few drops into the white chocolate. Use a toothpick or cake tester to gently swirl the food coloring into the white chocolate. Do not over mix the coloring into the white chocolate.
Using your hands, dip the top of each chocolate covered cookie into the marbled white chocolate. For a more marbled look, twist the cookie in the coloring. Gently shake off any excess chocolate back into the bowl.Add more drops of food coloring as needed to get the marbled look you want every 5-6 cookies.
Allow cookies to dry fully before storing or eating.