My bad, I was too brief. The Myconid silent speech ability would allow any Myconid to communicate telepathically. Not just spellcasters.

I homebrew a lot so it fits my world. NPC Myconids also cannot “see.” Major Fey are allergic to cold iron and cannot lie. That much homebrew is not for everyone.

My take is that every species/race should play different. In 5e, the difference between races is 3 abilities/skills and some flavor text. That’s pretty weak.

In my world, everything is earth normal unless influenced by magic or another plane. Maybe Fey isn’t right for Myconids. Maybe they should be associated with the negative plane instead. Decay, death… yes that works better.

I don’t know of any content exactly as you want it but …

There is some content in Fizban’s related to cursed coins from a Dragon Hoard.

or

Mold earth to make a sand mold of local silver coins joined by a small sprig.
Pour iron into the mold and let it cool.
iron to silver with Minor alchemy via 2nd level Transmutation ability. (one object only)
Prestidigitation to make it look appropriately weathered. (one object only)
Break them into individual coins.
Pawn them off in an hour
Profit?

Adventurers paid by crummy minor noble to determine how the counterfeiting was done and track down the culprit.

Use this site to generate the city if needed: https://watabou.github.io/

Clues: Smithy or tool proficiency to determine sand casting using extremely fine sand (rare). Arcanna check to determine Transmutation. Nature or local druid to find deposit of such fine sand. Stakeout to catch lackeys digging up sand for another batch. Lackeys lead to an abandoned bakery on the outskirts of the city, the Transmuter’s lair. Transmuter, mephit familiar, bandit type lackeys. Maybe a group of dwarven anarchists.

Plot twist: Transmuter is a philanthropist. The poor finally were able to attend the city carnival. Back taxes paid. Do they let her go if she promises to stop? Do they turn her in for the reward? Do they join her?

Battlemap for a bakery further down the page.
https://crossheadstudios.com/battlemaps/

Well met my Fungal Friend.

Alternatively, here is a crazy idea.

Myconid

Ability Scores: Choose one of: (a) Choose any +2; choose any other +1 (b) Choose three different +1

Size: Small or Medium

Speed: 30 ft.

Size: You are Medium or Small. You choose the size when you select this race.

Sunlight Sensitivity: You have disadvantage on attack rolls and on Wisdom (Perception) checks that rely on sight when you, the target of your attack, or whatever you are trying to perceive is in direct sunlight.

Sight: Myconids permanently have the blinded condition. This condition cannot be cured.

Spore Vision: Myconids constantly exude a near invisible cloud of spores through which they sense the world. You have blindsight with a range of 30 feet. Within that range, you can effectively see anything that isn’t behind total cover, even if you’re blinded or in darkness. Moreover, you can see an invisible creature within that range, unless the creature successfully hides from you.

Poison Resilience: You have advantage on saving throws you make to avoid or end the poisoned condition on yourself. You also have resistance to poison damage.

Silent Speech: You can speak telepathically to any creature within 30 feet of you. The creature understands you only if the two of you share a language. You can speak telepathically in this way to one creature at a time.

Fey Ancestry. Myconids originate from the FeyWylde. You have advantage on saving throws against being charmed, and magic can’t put you to sleep.

Languages: You can speak, read, and write the spore based Myconid language. The Myconid spore based language is non-auditory and silent but can be used for the verbal requirements of spell casting or magic item activation. You can read, write and understand Common and Undercommon but can only speak them telepathically. Myconids lack vocal cords. They are permanently incapable of speaking any language other than Myconid. This condition cannot be cured. No other race is capable of learning or using the Myconid language except through magical means.

Nature Sense: You have proficiency in the Nature skill.

Homebrew Balance Calc: Stat +12, Speed +0, Sunlight Sensitivity -3, Blindsite Beyond +4, Resistance and Adv 5, Telepathy with language 6, Fey +2, Language 0, Nature +2= 28

It makes for a strange character who needs to rely on other players for basic things but is very powerful in other ways. They tend to have agoraphobia, the fear of open places. Myconids like dark damp confined places like underdark caverns, thick fetid swamps, and warrens of inner city slums.