Celestial Blaze

A majestic and imposing wave of healing fire explodes out from a point you can see within the spell's range. Many will guard against and fight off the flames- which heal impartially-  so your casting will require more careful planning than most healing spells. Each creature in a 30-foot-radius Sphere centered on that point must make a Constitution saving throw. On a failure, each target regains Hit Points equal to 5d12 plus your spellcasting ability modifier.

Using a Higher-Level Spell Slot. The healing increases by 1d12 for each spell slot level above 5.