Any cake that uses cream cheese in the frosting should stay in the fridge until delivery time.
Make gumpaste flowers in advance and don’t put them on the cake until the last possible minute (either before leaving your shop or at the event site) because gumpaste can wilt in the fridge due to condensation.
Whenever dealing with a dark garnish on a white cake – especially anything with red or black food coloring – wait till the last possible minute to add it to avoid staining.
Good luck!
Kristen from Wicked Goodies, http://www.wickedgoodies.net/ << check out my website for free tips and tutorials on baking and cake design
