What you need3 Hat boxes in tapered sizes
This wedding craft project shows you how to make a collection box for those wedding cards.
Take your 3 hat boxes and cut the bases and lids out from each box, allowing a 1 inch edge so you have something to glue it to the next box with.
Obviously the top box lid only needs a small slit in it for the envelopes to go in. The bottom box doesn’t need its base removing either or all your cards will fall out.
Glue the 3 boxes together to form the cake.
Decorate the boxes with crepe paper icing and plastic roses.
Alternatively you may be able to pick up a wedding cake pinata which you can adapt by placing a hole in the top and sealing the bottom.