For the Cupcakes:
Preheat oven to 350 degrees F. Place paper baking cups in muffin pans, and set aside.
Melt candy bars and 2 tablespoons butter in a heavy saucepan over low heat, stirring until smooth. Let cool.
In a small bowl, whisk together flour, soda, and salt.
Cream together the sugar and 1/4 cup (1/2 stick) softened butter in a large mixing bowl at medium speed with an electric mixer until well blended. Add egg, beating just until blended.
Gradually add flour mixture to sugar mixture, alternately with buttermilk, beginning and ending with flour mixture. Beat at low speed just until blended after each addition. Beat in melted candy bar mixture and vanilla. Spoon batter evenly into baking cups, filling two-thirds full.
Bake until a wooden pick inserted in centers comes out clean, about 18 minutes. Remove from pan, and let cool completely on wire racks.
For the Witch Hats:
Place chopped chocolate in a microwave-safe bowl. Microwave at medium power for 2 minutes or until soft; stir until smooth.
Place wafer cookies on a rimmed baking sheet. Using a small paint brush, paint a thick layer of chocolate around bottom edges of cones. Center bottoms of cones on cookies. Refrigerate until set, about 15 minutes.
If necessary, microwave remaining chocolate on medium power for 30 seconds to thin. Paint outsides of cones with melted chocolate, and refrigerate until set, about 20 minutes.
For the Witchy Dirty Green Buttercream:
Place 1 tablespoon of the butter and candy bars in a microwave-safe bowl; microwave at medium power for 2 minutes or until soft. Stir until smooth.
Beat the remaining softened butter until creamy in a medium mixing bowl with an electric mixer. Add the sugar and warm melted candy mixture; beat until smooth and fluffy. Beat in 6 drops green food coloring until blended.
Frost tops of cooled cupcakes with a thick layer of frosting. Refrigerate until frosting is firm, if desired, about 15 minutes.
Top each cupcake with a Witch Hat. Cut licorice sticks into 1/2-inch and 2-inch lengths; place short sticks under hat for bangs and long sticks under hats for hair. Place cinnamon candies on cupcakes for eyes and candy corn for teeth. Makes 15 cupcakes.