Creating a treasure block with generation.

I want to create a grass block where I can use an item that digs the block, dropping a treasure item, then getting replaced by a normal dirt block. I also want to include this in terrain generation and if possible, have it generate across a certain area each minecraft day. My inspiration are the treasure spots from Animal Crossing. Is there any way to achieve this using Mcreator? Thanks!
Edit: Perhaps something quite similar to how the suspicious sand works in the new 1.20 update.