Preheat your oven to 350°F. In a large mixer bowl, combine the devil's food cake mix, water, vegetable oil, eggs, and chocolate fudge instant pudding mix. Beat everything on medium speed until well blended and smooth, making sure there are no lumps in the batter.

Line baking sheets with Silpat or parchment paper. Using a scoop or spoon, dollop even portions of batter onto the prepared baking sheets in round shapes—make 18 rounds for larger Whoopie Pies or 36 for smaller ones. Bake in the preheated oven for 7-10 minutes, depending on size, until the cakes are set and spring back to the touch. Once baked, let the cakes cool completely on a wire rack before decorating. I recommend keeping a close eye near the end of baking, as these cakes can go from perfect to overbaked quickly.

While the cakes cool, scoop the vanilla cake icing into a bowl. Add orange gel food coloring and mix thoroughly until the icing is uniformly orange and reaches your desired shade. You can adjust the intensity by adding a little coloring at a time. For a brighter and more festive look, I always start with a small amount and build up the color gradually.

Pair the cooled cake rounds by size. Pipe or spread the orange-colored icing onto the flat side of one cake from each pair, then gently sandwich with another cake. Repeat for all pairs, making sure not to overfill to prevent the icing from oozing out.

Sprinkle edible black glitter (or black sprinkles) over the assembled Whoopie Pies for a festive finish. For extra Halloween fun, you can use black licorice to create spider legs and attach candy eyes with a dab of icing, or stencil designs with confectioners' sugar using a small sieve. I think adding the candy eyes and licorice 'legs' turns these into adorable spider treats that kids love.