When stacking a wedding or birthday cake, the tiers can either be stacked directly on top of each other or by the use of separator plates and pillars. No matter how many tiers your cake is overall, when elevating the top tier of your cake you need to follow the proper precautions and instructions to ensure your cake is stable and will not sink, tilt or fall over.
Place frosted cakes on a clean work surface. Take bottom tier of the cake and carefully insert a wooden dowel rod into the centre of the cake. Use a pencil to mark a line on the rod where it peeks just even with the coat of frosting. Use a saw or heavy wire cutters to cut the dowel rod at that line and use that cut rod to cut out four more rods that are even to the first dowel rod you cut.
Insert the centre wooden dowel rod back into the cake. Take your separator plate and carefully press it on top of the cake without destroying the buttercream or fondant surface. Lift it up and set it aside. Note the four impressions left by your separator plate where the supports need to be placed (they should look like four dots). Insert the four remaining wooden dowels into the spots that were marked by your separator plate.
Place your separator plate on the cake with the pillar feet facing upward and set aside. Use a cake spatula to lift your top tier of cake onto the second separator plate. Ensure that the cake is evenly placed on the plate. Set the top tier aside.
Place four plastic pillars on top of the separator plate's feet for the bottom tier. Look under the top tier's separator plate as you lift the cake above the pillars and carefully line up the support feet from the bottom of the top tier plate with the pillars. Ensure that the cake is secure on the pillars and that each of the four feet is locked in with the plastic pillars.
Take the cake apart for transport. Construct the cake on-site at your wedding reception or party location to ensure stability. Leave pillars plain or decorate with flowers, leaves or sugar pieces.