Essence Dono

Touch a willing creature and expend a number of your own hit dice equal to your proficiency bonus. The target recovers 1 of its own expended hit die for each hit die you expend during the casting of this spell.

An unwilling creature must succeed on a Constitution saving throw or be forced to accept your hit dice.

At Higher Levels. When you cast this spell using higher level spell slots, the number of expended hit dice the target recovers for each of your expended hit dice increases: 2 with a 5th-level slot, 3 with a 7th-level slot, and 4 with a 9th-level slot.