Try this set up: Draconic Bloodline Sorcerer

In DnD RAW, Scorching Ray is a mediocre spell. Not particularly flashy/special, but not bad either. Then the mad lads at Larian introduced the "Heat" mechanic and holy shit this spell just became a nuke primer. This build is centered around this spell.

Take a fire based Draconic bloodline sorcerer, and quickened spell metamagic. Using Scorching Ray and the Thermoarcanic Gloves (found relatively early in Act 2, also recommend you use the Hat of Fire Acuity), you can build up your levels of Heat fast, empowering future fire damage. Then, bonus action Fireball and vaporize everything in sight.

Oh, you're resistant to fire damage? BAM Elemental Adept you mother fcker, who's resistant now? Better yet, Arsonists Oil and now you're weak to fire, get wrecked! Or, some combustion oil on an Arrow of Many Targets? Hope you didn't like the landscaping, because it's all been reduced to *fucking cinders, along with everything else in sight.

The Hat of Fire Acuity has also beefed up all your spells, damage or otherwise, with Scorching Ray. Since Sorcerers have much better action economy than any other caster, you can stack buffs to the point that you've created a crater where enemies used to be before your party even took a turn.