I made these before but can't find the exact recipe. It used a bought cake mix, and I think it only required adding water, no egg, or oil. The recipes I am finding today call for adding egg or yolk, oil and maybe water. Do you think if I got one of the cake or brownie mixes that say add only water, that it would work ok? Hmmm, or do I have to experiment, and "HAVE to eat the testings". Thanks.