Consider a Wizard 13/Sorcerer 7 multiclass, who happens to have the Twinned Spell metamagic option:
When you cast a spell that targets only one creature and doesn’t have a range of self, you can spend a number of sorcery points equal to the spell’s level to target a second creature in range with the same spell (1 sorcery point if the spell is a cantrip).
To be eligible, a spell must be incapable of targeting more than one creature at the spell’s current level. For example, magic missile and scorching ray aren’t eligible, but ray of frost and chromatic orb are.
Now this character casts simulacrum:
Can a Sorcerer use Twinned Spell to create 2 duplicates of himself (or someone else)?
Can a Sorcerer use Twinned Spell to create 1 duplicate for 2 different targets at the same time?