Line a baking sheet with parchment paper, and evenly place the Oreos about 2-2½ inches apart. Set aside.
In a medium, microwave-safe bowl, melt the baking chips at 30 second intervals. Stir well until completely smooth.
Add 2 Tbsp. vegetable oil to the melted white baking chips, and stir well until thoroughly combined.
Spoon the melted white chocolate over each Oreo cookie, allowing it to slightly drip over the sides.
While the icing is still wet, place a cut marshmallow to one side of the top of the cookie, and add 2-3 mini-M&M “buttons” along the icing.
Allow the cookies to rest at room temperature for 2 hours or until the white chocolate is completely hardened. Do not place the cookies to harden in the refrigerator!
Once the icing has set, decorate the snowman’s head. Using the black edible ink, dot on some eyes and a mouth onto the marshmallow. Push an orange sprinkle “nose” into the marshmallow.
Draw stick-shaped arms onto the hardened white chocolate covering the cookie.
Tie the scarf around the base of the marshmallow using a thin strip of licorice rope.
Serve and enjoy!