Paris Jackson has a lot to smile about this week ... because she's hard at work on her latest album after she recently got engaged!

Paris was all smiles Monday, flashing her engagement ring outside a recording studio in L.A., grabbing a food delivery from Erewhon Market.

The tatted-up daughter of Michael Jackson was looking casual in flared jeans, a tank top and sandals. She's been working on her music with Linda Perry, who's producing the album.

Paris just got engaged to music producer Justin Long, who's also in her band, in December.