Discovery of Witches trilogy, Deborah Harkness (if you haven't read them, read them!)
And Outlander, Diana Gabaldon (got to the end of book 2 and realised there are 8 in the series and just thought ffs)
Basically back-int-day (1800's or before) novels, romance but not 'don't be so soft' kind of romance or just generally witchy and supernatural (not silly, though).
Don't all have to be in the same category, any of each will do!
Thanks in advance!