Planet Cake’s #1 secret is how we achieve the shine on our cakes, I get asked this question regularly and it is the #1 question asked in our forum.
There are a few home methods for getting a shine on your cake.
The first is to use jam mixed with a little bit of hot water. Mix it so it is a jelly like consistency and apply it to your cake with a pastry brush. Make sure the jam is a very cheap jam with jelly only and no pips or bits. Cheap apricot jam usually works well. Apply the jam as close to your event as possible. The other method is to use olive oil cooking spray. Apply the spray to a paint brush and coat the icing you want to be shiny the day of your event as it only lasts 24 hours.
The professional product that creates the Planet Cake famous shine is Cold Flan Glaze - ready to use setting clear gel for decoration of tortes and glazing of fruits. The brand we use is Cristaline and we get it from a supplier in big tubs. Unfortunately we have not seen it for sale in smaller quantities. We usually just brush it on with a pastry brush.