Learning Eldritch Blast, but for Intelligence spellcasting

Question

Is there a way for an Eldritch Knight to learn the Eldritch Blast cantrip and be able to use Intelligence as the spellcasting modifier for it? The Spell Sniper and Magic Initiate feats both have the spellcasting ability score dependent on the class' spell list, so that's a no go. All stats except for Charisma meet the prerequisite for multiclassing so it's an option to consider, but I prefer not to if possible.

I feel like a fighter archetype named Eldritch Knight should be able to learn Eldritch Blast using Intelligence, but I have no idea how to do so without homebrew. I appreciate the help.

Answer 1

The short answer is "No".

Your class uses the wizard spell list for selecting spells according to the Eldritch Knight class description:

When you reach 3rd level, you augment your martial prowess with the ability to cast spells. See Spells Rules for the general rules of spellcasting and the Spells Listing for the wizard spell list.

You learn two cantrips of your choice from the wizard spell list.

The Eldritch Knight Spellcasting table shows how many spell slots you have to cast your wizard spells of 1st level and higher.

Sadly, Eldritch Blast is only on the Warlock spell list, and even then the Warlock 'Spellcasting Ability' section of the class description says:

Charisma is your spellcasting ability for your warlock spells

The only non-homebrew ways to access that spell are with the Spell Sniper and Magic Initiate feats or to multi-class to Warlock, all of which still leave you with Charisma as the spellcasting ability. It kinda sucks that an Eldritch Knight can't do all things 'Eldritch', but that's the way the class is written.

Answer 2

Yes, use the wondrous All-Purpose Tool

Track down an All-Purpose Tool (uncommon) magic item (Tasha's Cauldron of Everything, p. 119), and multiclass one level of Artificer so that you can attune to it. Then, it lets you:

Choose a cantrip that you don't know from any class list. For 8 hours, you can cast that cantrip, and it counts as an artificer cantrip for you. Once this property is used, it can't be used again until the next dawn.

So you can choose and cast Eldritch Blast with it, and "intelligence is your spellcasting ability for your artificer spells".