How do you earn gold candy?

You can only buy them, well, now and then I've seen a few promotions in-game where you might get some but apart from that you have to purchase them yeah. 

I'm at level 1000 and have now started to earn gold bars win I complete a level - not sure when it started - there is now a piggy bank that says its full or gives the number of bars in the bank

Hi @normaB1, I am trying to think of we have any challenges where you can win the gold bars but nothing is coming to mind at the moment.  I am wondering if the sugar drop challenge might throw some gold in now and then.  Try the sugar drop challenge to see if you get anything.  You can win up to 13 free boosters every 8 hours.    Read more about it here:  https://care.king.com/en/blog/article/candy-crush-sugar-track-is-here and if you want some of the best levels to play the sugar drop challenge check it out here:  https://candycrushsagaallhelp.blogspot.com.es/search/label/Sugar%20drop%20challenge