My method for icing cakes is quite easy, but it does take time. Firstly, cut the domed top off the cake, and turn it upside down on a piece of baking parchment, so that the bottom of the cake is facing upwards. The bottom is usually flatter so it gives a better finish on the marzipan and icing. I try to feed the cake at least once ‘upside down’, so that the alcohol isn’t all concentrated on the bit of the cake that gets cut off.
Secondly, fill in all the pits, nooks and crannies all over the cake with blobs of marzipan. The smoother the surface before applying the marzipan layer, the better. If it’s an extra special cake, roll a thin sausage of marzipan to smooth into the base of the cake, where the icing will meet the board.
Thirdly, roll out a strip of marzipan reasonably thick and wide enough to go up the sides of the cake. Then cut off the ends and stick it to the sides of the cake with sieved apricot jam. Then roll out a disc for the top of the cake, stick it on with jam, and smooth the join of the marzipan. It needs to be left to dry for 24 hours, ideally.
Next goes on the icing. I normally use ready-to-roll or fondant icing (although this year I tried royal icing for the first time, with mixed results!). Roll it out quite thick in a circle big enough to go over the top and sides of the cake, but not too big. Use gin (or another clear alcohol) to wet the marzipan and make it sticky, then gently place the icing over the marzipan, smoothing it out carefully over the top and sides of the cake. In theory doing this carefully should avoid air bubbles forming, but I usually lose patience and cover up any bubbles with decorations instead! Then trim off the excess around the bottom. I always use a ribbon around the base of the cake, so it looks neat. Again, it needs 24 hours to dry before being carefully placed on a cake board (avoiding touching the icing) and decorated.