Met today with my siblings and talked about the cake. Brother suggests only using the white cake mix and add your flavors from there. He suggested adding some dutch chocolate in the mug for a chocolate flavor. Another suggested using lemon juice for the water and lemon zest to taste. I used a chocolate cake mix and did not spray the mug and it just dropped out. I will make a bunch and then make individual layer cakes for the family. Would be cute to make the white cake mix for Easter and decorate them.
Just emailed them the versions found here.