these 'puffballs' are called 'earth balls', and unlike true puffballs are poisonous

try googling 'scleroderma earth balls'

if you cut them in half when they're just beginning to mature, the centre is flushed a lovely purple

Here is a link that might be useful: photos

All puffballs tend to have black spore mass inside when mature. Your photos look like scleroderma citrinum, a poisonous mushroom.

Here is a link that might be useful: Scleroderma citrinum