Preheat your oven to 350°F.
Combine the Devil's food cake mix, water, vegetable oil, eggs, and pudding mix in a large mixer bowl and beat on medium until well blended.
For larger Whoopie Pies, add 18 evenly sized scoop fulls of the batter into Silpat-lined or parchment paper lined baking sheets in a round shape.
For smaller Whoopie Pies, make 36 batter circles.
Bake 7-10 minutes, depending on the size of the pies.
Let fully cool before decorating.
Pipe the icing onto the flat side one Whoopie Pie cake and top with a second cake.
Sprinkle on the sprinkles