Double

You speak a word of power, greatly empowering your magic. The first spell you cast on your next turn has its number of initial damage dice doubled. The spell must deal instantaneous damage, must not require concentration, and can be no higher than 5th level. If the spell requires an attack roll, it doubles the number of targets instead.

At Higher Levels. When you cast this spell using a spell slot of 8th or 9th level, you triple the number of initial damage dice or number of targets.

Sample Spells