In a large mixing bowl, add cake mix, water, eggs, and oil. Using a hand or stand mixer, mix on low speed for 1 minute, and then on medium for 1 minute. Incorporate the hot cocoa mix.
Place icing in piping bag and frost cupcakes. Add two mini Oreos for the Mickey ears. Glue buttons on cupcake wrapper, if desired for this cupcake recipe. You can decorate as Minnie cupcakes too.