Preheat your oven to 350 degrees F and line two baking sheets with parchment paper.

In a large mixing bowl, stir together the chocolate cake mix, oil, and eggs until a thick dough forms.

Scoop the cookie dough into 2-tablespoon-sized balls and place them on the prepared baking sheets about 2 inches apart. Bake for 9-11 minutes, or until the edges are set. Let the cookies cool for 5 minutes before moving them to a wire rack to finish cooling.

Place the semi-sweet chocolate chips in a microwave-safe bowl. Pour the heavy cream over the chocolate chips and microwave for 45 seconds. Let the bowl rest for 1 minute, then whisk the chocolate and cream together until smooth and glossy. Set the ganache aside for 5-10 minutes to cool and thicken slightly.

Spread a heaped spoonful of ganache over each cooled cookie. Press a Vanilla Wafer Cookie near the bottom of each cookie to form the muzzle. Add two candy eyes above the muzzle and press whole chocolate-covered pretzel twists into the top edges of the cookie for antlers. Place a small amount of ganache on the back of the red chocolate candy and place it in the center of the wafer for the nose.

Allow the ganache and decorations to set before serving.