Preheat the oven to 350 degrees Fahrenheit.
Lightly grease cookie sheets or line with nonstick baking mats. In the bowl of an electric mixer, mix together cake mix, melted butter, vanilla and egg until fully combined.
Form and roll dough into walnut-sized balls and place at least 2" apart on prepared cookie sheets. Bake for approximately 8 minutes.
Allow cookies to cool slightly, then press an orange M&M into the center of HALF of the cookies (before they're completely cooled) to be the turkey's beak.
Allow cookies to cool completely, then prepare the buttercream frosting by creaming together the softened butter, powdered sugar, vanilla, and just enough milk for thinning together in a bowl of an electric mixer (add the milk 1 Tbsp. at a time, mixing in between). You want it to be nice and creamy, but not runny at all. Mix it for 4-5 minutes to make it extra fluffy and delicious!
Reserve 2 Tbsp. frosting and put it in a small bowl. Stir in orange food coloring until desired color is reached.
Frost the cookies with the white frosting and make them into sandwiches. Insert 5-6 candy corns into the frosting around the sides for the turkey feathers.
Transfer orange frosting to a sandwich-sized zip top bag, snip a TINY piece off the corner of the bag, and pipe on two orange turkey legs to the bottom of each cookie.
Add a dot of frosting to the back of two candy eyes and place them just above the beak. Enjoy!