This mod is one of the many that serve to add an additional selection of spells from 1st level spells up to 9th level for all classes and their spell list (includes the Spell Sniper and Ritual Caster spell lists), as well as add additional spells to class spell lists following the DnD 5e's Tasha's Cauldron of Everything source material. My purpose in creating this mod was to be implemented in a number of other mods (especially my own), though it is entirely capable of being used alone for the 1st to 6th level spells. Lastly, the spells that would serve as ritual spells from 5e Spells added by this mod operate in a similar fashion by only those considered ritual casters, being Bard, Cleric, Druid, Wizard, Artificer and Warlocks with the Book of Ancient Secrets invocation. As such, these spells don't possess the ritual tag currently but will be usable without a spell slot while outside of turn based mode/combat. This mod does not modify any base game spells.

In any case, many of these spells were largely straightforward to add to the game while some are admittedly questionable but get the job done. There are also the following additional mods you might enjoy (this is not a recommendation since far too many people interpret me listing these as such and are just frequently asked for mods):

• Homebrew Spells - Adds additional spells not found in 5e at all as they are created by third party individuals.
• War Caster 5e - Useful for those wanting the feat to work with more than just Shocking Grasp. 
• 5e Spells Last Until Long Rest - For those that would like some of the added spells implemented in this mod to last until you finish a long rest.
• 5e Spells - Larian Durations - Adjusts durations for various spells to match that of base game spells.
• Secrets Scrolls for 5e Spells - Adds scrolls with spells contained in this mod.
• Actual Green Flame Blade - Name says it all.
• Spell List Combiner - Helps in arranging the spells in alphabetical order and by level if that's desired since my method of adding the spells through the script extender goes against it (and have no idea where to start even attempt that on my own).
• Minthra's Configurable Enemies - Adds spells from this mod to enemies.

In any case, the spells added in this mod are:

• Booming Blade
• Control Flames
• Create Bonfire
• Druidcraft
• Frost Bite
• Green-Flame Blade
• Gust
• Lightning Lure
• Magic Stone
• Mind Sliver
• Mold Earth
• Prestidigitation
• Primal Savagery
• Shape Water
• Spare the Dying
• Sword Burst
• Thunderclap
• Toll the Dead
• Vicious Mockery
• Word of Radiance

1st Level Spells

• Absorb Elements
• Beast Bond
• Catapult - I implemented this spell one way but realized it could be done another way. However, to prevent issues with current saves, I've made the old one obsolete and noticeable in the spell lists for the time being. People can simply remove it from the hotbar, respec or swap it out for another spell for the time being. In a few updates, I'll remove it so hopefully most with the old version will have removed it by then.
• Cause Fear
• Ceremony - The Bless Water spell container requires the script extender to work. You or the target must have a "Water" item in your inventory in order for it to be converted into Holy Water.
• Chaos Bolt - Requires the script extender to work. Also, specifically haven't accounted for the ability to target a third creature or more currently (maybe never).
• Detect Evil and Good
• Detect Magic - You gain an aura that places a status on creatures that have spell slots within 9m of you. You also gain a temporary spell on the right side of the hotbar that allows you to place an effect on a creature that prevents them from hiding or becoming invisible while they remain within the aura's radius.
• Earth Tremor
• Frost Fingers
• Tasha's Caustic Brew
• Unseen Servant - It summons an full on, literally invisible Mage Hand-like creature with a swirling circle underneath it. It cannot attack at all whatsoever but it can use the Prestidigitation cantrip since it's kind big for cleaning. Considering adding in the ability to throw objects but without causing them to deal any damage (which excludes throwing healing potions).
• Zephyr Strike

• Aganazzar's Scorcher
• Borrowed Knowledge
• Continual Flame
• Dragon's Breath - The animation and FX doesn't work when using it on like familiars and other summons. And on the flip side, there's no way to use it using the spellcaster's ability modifier as it'll automatically default to the non-summon creature's spellcasting ability modifier instead. There's also a glitch involved in not only the appearance of the action's DC where it factors in the summon's Strength or Dexterity modifier (but it actually doesn't), it also seems to only partially provide the spellcaster's modifier sometimes. I might have a fix for it but that's the way it operates currently I'm afraid.
• Dust Devil
• Flock of Familiars
• Healing Spirit - Summons a (cat) spirit that must be within 5 feet/2m of a creature to allow the summoner to heal a creature. Due to certain limitations with checking for spellcasting ability modifier, simply gave the healing 6 charges, which is the max it would've given otherwise.
• Kinetic Jaunt
• Maximillian's Earthen Grasp
• Mind Spike
• Nathair's Mischief - Requires the script extender to work.
• Rime's Binding Ice
• Shadow Blade
• Snare
• Snowball Storm
• Suggestion - Removed from spell lists for the time being until I think of a suitable enough effect.
• Summon Beast
• Tasha's Mind Whip
• Vortex Warp
• Warding Wind
• Wither and Bloom - The healing spell uses the creature's Constitution modifier instead of the caster's spellcasting ability modifier because setting that up is difficult at the moment and currently alludes me.

• Ashardalon's Stride
• Catnap
• Create Food and Water
• Enemies Abound
• Erupting Earth
• Flame Arrows
• Intellect Fortress
• Life Transference - Requires the script extender to work.
• Melf's Minute Meteors
• Motivational Speech
• Nondetection
• Spirit Shroud
• Summon Shadowspawn
• Thunder Step - The explosion at your previous location has been accounted for in the script extender due to system limitations with teleporting another creature with you.
• Water Walk

4th Level Spells

• Charm Monster
• Guardian of Nature
• Raulothim's Psychic Lance
• Shadow of Moil - Credit to drkekyll
• Summon Elemental

5th Level Spells

• Commune with Nature - Since it working exactly like RAW isn't all that doable, it instead grants the caster expertise in the Nature and Survival skills for 100 turns. Not much but when comparing it to Skill Empowerment, which is 1 hour and requires concentration and lets you pick any skill, doesn't seem entirely outlandish. Especially with it being a ritual spell.
• Conjure Volley
• Far Step
• Holy Weapon
• Negative Energy Flood
• Raise Dead Largely redundant for the moment due to Revivify and it not being modified to differentiate.
• Rary's Telepathic Bond Potentially fixing later.
• Skill Empowerment
• Steel Wind Strike - The teleport action you gain after using the spell must specifically target one of the previously targeted creatures, even if the spell missed one/any of them.
• Swift Quiver
• Summon Draconic Spirit Fixing later.
• Synaptic Static

For those using the named optional mod, the changes it makes to base game spells includes the following. Note however, I don't make plans to add any additional base game changes to it and was largely made to help fix some people's playthrough saves. You can also one of the other Optional mods in combination with this to adjust some of the changes back to the base game as desired (but if you're using both, it's redundant to have any since the base mod no longer modifies base game spells).

• Barkskin - Changed duration to 600 turns instead of until long rest
• Call Lightning - Changed duration to 100 turns instead of 10 turns and modified it to actually target a specific location instead of being able to use it anywhere similar to the source material. Rather than a thundercloud, it'll be the radius of the rain and creatures that can be damaged will have the status that allows them to be targetable by the temporary spell in the far right side of the hotbar, which will be free with the initial casting of the spell.
• Chromatic Orb - Remove surface creation effects and increased damage of each spell of each level by one die (2d8 to 3d8, etc.), excluding Thunder damage which is the only one correct
• Compelled Duel - Changed the duration to 10 turns instead of 3 turns
• Crown of Madness - Changed the duration to 10 turns instead of 3 turns
• Darkness - Changed duration to 100 turns and added an Item version. However, the Item version doesn't fully operate like the Cloud version, such as being prevented from being targeting or being targeted by those outside of the darkness area or being seen. The most it does is apply Blinded to those within its range and lowers the obscurity level to heavily obscured.
• Daylight - Changed duration to 600 turns instead of until long rest
• Detect Thoughts - Changed duration to 10 turns instead of until long rest
• Disguise Self - Changed duration to 600 turns instead of until long rest
• Divine Favor - Changed duration to 10 turns instead of 3 turns
• Enhance Ability - Changed duration to 600 turns instead of until long rest
• False Life - Changed duration to 600 turns instead of until long rest
• Feign Death - Changed duration to 600 turns (and added a dismiss spell) instead of 10 turns
• Fireball - Changed area radius to 6m instead of 4m
• Flame Blade - Change duration to 100 turns instead of until long rest
• Fly - Changed duration to 100 turns instead of 10 turns
• Fog Cloud - Changed duration to 600 turns
• Gaseous Form - Changed duration to 600 turns instead of until long rest
• Goodberry - Changed its hit point regain to 1 and number of berries to 10 instead of 1d4 hit points and 4 berries
• Hail of Thorns (Fix provided by Djmr to apply the spell's effect on a ranged weapon attack specifically instead of within the spell itself)
• Heat Metal - Changed it so it applies to a target's armor first instead of their weapons
• Hunter's Mark and Hex - Changed the 1st level version to 600 hours from until long rest, so 3rd level and above become until long rest since any duration above 1 hour is kind of redundant.
• Hypnotic Pattern - Changed duration to 10 turns instead of 2 turns
• Ice Knife - Removed the ice surface creation effect.
• Invisibility - Changed duration to 600 turns instead of 10 turns
• Magic Weapon - Changed duration to 600 turns instead of until long rest
• Mirror Image - I haven't made the change in this mod but another modder has to get it closer to 5e (though still not 100%). Check out their mod if you desire such a change.
• Pass Without Trace - Changed duration to 600 hours instead of until long rest
• Protection From Energy - Changed duration to 600 turns instead of until long rest
• Protection From Evil and Good - Changed duration to 100 turns instead of until long rest
• Protection From Poison - Changed duration to 600 turns
• Sanctuary - Added an actual spell save DC to the effect
• Shield of Faith - Change duration to 100 turns instead of until long rest
• Speak with Animals - Changed duration to 100 turns instead of until long rest
• Speak with the Dead - Changed duration to 100 turns instead of until long rest
• Spirit Guardians - Changed duration to 100 instead of 10 turns and increased the radius from 3m to 4.5m.
• Warding Bond - Change duration to 600 turns instead of until long rest

How to Install

I would recommend installing mods using the BG3 Mod Manager, full stop.