Solasta: Crown of the Magister

Easily done in the Dungeon Maker. Add a good-sized room as your base. Then add a chest from the "Gadgets" tab (looks like a chest) and then select the chest icon. Under "Explicit Items" go to "Add Element" and then to "Adventuring Gear" or search for "gp" (not gold) and add several instances of "250d1 gp" I did around 10 instances of gold per chest.

Edit: larger amounts of gold can seemingly be added now, so use the largest you can!

Once you've added several instances to the chest, use the "duplicate" function on the chest and add it around the room. Make sure the chest is facing a direction that allows it to be opened (this is why large rooms are best) and then save your map. Now select "play" directly from the map screen and add your adventurers. Once you've looted all the chests the cheevo should pop!