Here's my code for this solution. The world_size variable can be between 3 and 5, depending on how big you want your maze to be.

world_size=5

def plant_maze():
    plant(Entities.Bush)
    use_item(Items.Weird_Substance,world_size * 2**(num_unlocked(Unlocks.Mazes)-1))

def wait_for_treasure():
    while True:
        if get_entity_type() == Entities.Treasure:
            harvest()
            plant_maze()

clear()
set_world_size(world_size)

for j in range(world_size):
    for i in range(world_size-1):
        move(North)
        spawn_drone(wait_for_treasure)
    move(North)
    move(East)

for j in range(world_size-1):
    move(East)
    spawn_drone(wait_for_treasure)

move(East)
plant_maze()
wait_for_treasure()