Spell Slinger

This feat gives you 2 Spell Slinging Points. Whenever you cast a spell of level 1 or higher, you can use your reaction to cast the spell again, or another spell of the same level without expending a second spell slot (you must still have the material components). If the spell you are casting again is an attack spell, then you double the amount of damage dice, and if the spell is third level or higher, you add one more damage die. You regain all Slinging Slots at the end of every long rest.

 You can only duplicate a spell as long as you have a free hand, material components, you could cast the spell usually and neither of them requires concentration.