Eronin's Mnemonic Enhancer

Casting this spell strengthens your mind and memory, allowing you to prepare additional spells. When you cast this spell just before you begin to prepare spells following a long rest, you can prepare up to 3 additional levels of spells in any combination. For instance, you could prepare an additional 2nd level spell and a 1st level spell, or three 1st level spells. At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, you can prepare 1 additional level of spell for every spell slot level above 3rd