Form the remaining marzipan into 11 balls to represent all the Apostles, minus Judus. Using some apricot jam, stick the marzipan balls around the edge of the cake.
Place the cake under a pre-heated grill to lightly caramelise and brown the marzipan - whatever you do, don't walk away from it! It can go from perfectly toasted to burned in seconds. Leave to cool before transferring the cake to a serving plate.