As answered aboveby Astralbee and by JavaLatte, both statements are correct English. The second would be understood correctly even though the dessert does not yet exist; it is similar to the sentence "the decision is yours to make" which means you must make the decision.
The word "yours" may be taken as referring to the mess or cake, but it may also be taken as referring to the assigned task of cleaning or making.
I have heard statements like the second used in the course of organising a shared meal, where people are ensuring that they bring different items of food. I regard it as correct.