Versatile Spellcaster with prepared caster.

[Yogibear41]

If I qualify for Versatile Spellcaster by having the ability to spontaneously cast some spells but not all spells would I be able to sacrifice two lower level spells to cast a spell I would normally have to prepare?

Say I am a Sorcerer 1/Wizard 3. Can I sacrifice two 1st level wizard spells to cast a 2nd level wizard spell I had in my spell book but I did not have prepared? Could I use two 1st level wizard spells to cast a 2nd level wizard spell that I did have prepared but not use up the prepared slot when I cast it? Could I use two 1st level sorcerer spells to do either of the following with a 2nd level wizard spell?

[Biffoniacus_Furiou]

Versatile Spellcaster specifically says you need to spend two spell slots of the same level to cast any spell you know of one level higher. So you would need to leave two 1st level Wizard spell slots empty to spend them activating this feat. A spell slot is no longer available if it has a spell prepared in it, the slot gets spent to prepare the spell.

[Yogibear41]

That being said, I could use 2 of my 1st level sorcerer spell slots to cast a 2nd level wizard spell as well then correct?

[Troacctid]

No. You can't use slots from one class to cast spells from another class.

[Biffoniacus_Furiou]

That being said, I could use 2 of my 1st level sorcerer spell slots to cast a 2nd level wizard spell as well then correct?

That's a question for your DM, as it's a bit of a polarizing question around here. On one hand, Versatile Spellcaster says it allows you to cast any spell you know of one level higher than the slots spent, not a spell you know from the class list that you spent the slots from. On the other hand, each class has a built-in limitation that says you cast [class] spells using that class's spell slots.