GiftCards.com has a promotion on Happy Gift Cards. You can earn 10% back in G-Money Rewards points on Happy Gift Card purchases, from 2/18/19 to 3/1/19. Happy Gift Cards can be used at a variety of merchants that are listed on the card itself, and its possible to use them for purchases of other gift cards as well.
You can do even better if you go through a shopping portal. Lemoney for example is offering 4% cashback on purchases of Happy Gift Cards at GiftCards.com. You can check all cashback rates at Cashback Monitor.