Make antlers 1 day in advance. Print or copy the antler pattern and tape it to a cake board. Cover with parchment paper.
Melt a 3/4th of the dark cocoa Candy Melts candy in a disposable decorating bag according to package directions. Cut a small point off of a disposable decorating bag and fill with the melted candy melts. Outline and fill in the antler pattern with the candy melts decorating bag. Reverse the pattern and repeat for the opposite antler.
Chill until firm for about 10 to 15 minutes. Carefully remove from the cake board and turn over the candy antlers on parchment paper.
Attach pretzel rods to antlers. Melt remaining 1/4th dark cocoa Candy Melts candy in a tall dipping container according to package directions. Dip two pretzel rods halfway in candy then immediately place the dipped pretzel rods on the back of each antler. Chill until firm, about 10 to 15 minutes.
Make frosting. In a large bowl, cream ½ cup and 2 tablespoons butter with the equal amount of shortening from the chocolate and vanilla frosting ingredients with an electric mixer.
Remove ¼ cup from the mixture and set aside in a small bowl.
Make chocolate frosting. Add cocoa powder and vanilla and mix until smooth. Gradually add one cup of sugar at a time, beating at medium speed. Scrape down slides frequently. Set aside for later.
Make vanilla frosting. Add vanilla to the shortening and butter mixture that was set aside in a small bowl. Gradually add powdered sugar, a small amount at a time, and beat until combined. Gradually add milk, a small amount at a time, until reaching piping consistency. Set aside for later.
Make cake. Preheat the oven to 350? and spray two 6 inch round baking pans with non-stick spray.
In a medium bowl, combine the flour, baking soda, and salt.
In a separate microwavable bowl, melt the chocolate and butter until melted (around 2 minutes). Stir until smooth and transfer to a large bowl.
Add sugar to melted chocolate and beat with an electric mixer until well combined. Add one egg at a time and vanilla, then mix well.
Add in flour mixture alternately with milk and beat until blended and smooth.
Pour into prepared pans and bake for 32-36 minutes or until a toothpick inserted into the center of the cake comes out clean. Cool for 15 minutes in the pan, then place on a cooling grid to cool completely.